address unmatched_returns in cluster metadata code

[jrwest]

the following dialyzer errors no longer appear with this commit:

hashtree_tree.erl:343:
Expression produces a value of type hashtree:hashtree(), but this value is unmatched

hashtree_tree.erl:360:
Expression produces a value of type hashtree:hashtree(), but this value is unmatched

hashtree_tree.erl:368:
Expression produces a value of type hashtree:hashtree(), but this value is unmatched

hashtree_tree.erl:376:
Expression produces a value of type hashtree_tree:tree(), but this value is unmatched

riak_core_broadcast.erl:301:
Expression produces a value of type [['ok' | [any()]]], but this value is unmatched

riak_core_broadcast.erl:326:
Expression produces a value of type 'ok' | ['ok' | ['ok' | [any()]]], but this value is unmatched

riak_core_broadcast.erl:334:
Expression produces a value of type 'ok' | ['ok' | ['ok' | [any()]]], but this value is unmatched

riak_core_broadcast.erl:338:
Expression produces a value of type 'ok' | ['ok' | ['ok' | [any()]]], but this value is unmatched

riak_core_broadcast.erl:351:
Expression produces a value of type 'ok' | ['ok' | ['ok' | [any()]]], but this value is unmatched

riak_core_broadcast.erl:383:
Expression produces a value of type 'ok' | ['ok' | ['ok' | [any()]]], but this value is unmatched

riak_core_broadcast.erl:452:
Expression produces a value of type ['true'], but this value is unmatched

riak_core_metadata_exchange_fsm.erl:184:
Expression produces a value of type ['ok'], but this value is unmatched

riak_core_metadata_manager.erl:332:
Expression produces a value of type atom() | tid(), but this value is unmatched

riak_core_metadata_manager.erl:337:
Expression produces a value of type {'ok','cluster_meta_manifest'}, but this value is unmatched

riak_core_metadata_manager.erl:402:
Expression produces a value of type 'ok' | {'error',_}, but this value is unmatched

riak_core_metadata_manager.erl:560:
Expression produces a value of type atom() | tid(), but this value is unmatched

riak_core_metadata_manager.erl:599:
Expression produces a value of type atom() | {'error',_} | tid(), but this value is unmatched

Review:

• verify riak_test cluster_meta_basic still passes (NOTE: there is known, unrelated intermittent failure)
• verify dialyzer errors above are gone
• verify there were no missed dialyzer errors in cluster metadata files

A useful grep pattern for review: "\(riak_core_\(broadcast\|metadata\)\|hashtree_tree\)"

[rzezeski]

Verified that said warnings were removed by running dialyzer before
and after and doing diff between runs.

$ diff -u d.txt d2.txt | grep '^-'
-hashtree_tree.erl:343: Expression produces a value of type hashtree:hashtree(), but this value is unmatched
-hashtree_tree.erl:360: Expression produces a value of type hashtree:hashtree(), but this value is unmatched
-hashtree_tree.erl:368: Expression produces a value of type hashtree:hashtree(), but this value is unmatched
-hashtree_tree.erl:376: Expression produces a value of type hashtree_tree:tree(), but this value is unmatched
-riak_core_broadcast.erl:301: Expression produces a value of type [['ok' | [any()]]], but this value is unmatched
-riak_core_broadcast.erl:326: Expression produces a value of type 'ok' | ['ok' | ['ok' | [any()]]], but this value is unmatched
-riak_core_broadcast.erl:334: Expression produces a value of type 'ok' | ['ok' | ['ok' | [any()]]], but this value is unmatched
-riak_core_broadcast.erl:338: Expression produces a value of type 'ok' | ['ok' | ['ok' | [any()]]], but this value is unmatched
-riak_core_broadcast.erl:351: Expression produces a value of type 'ok' | ['ok' | ['ok' | [any()]]], but this value is unmatched
-riak_core_broadcast.erl:383: Expression produces a value of type 'ok' | ['ok' | ['ok' | [any()]]], but this value is unmatched
-riak_core_broadcast.erl:452: Expression produces a value of type ['true'], but this value is unmatched
-riak_core_metadata_exchange_fsm.erl:184: Expression produces a value of type ['ok'], but this value is unmatched
-riak_core_metadata_manager.erl:332: Expression produces a value of type atom() | tid(), but this value is unmatched
-riak_core_metadata_manager.erl:337: Expression produces a value of type {'ok','cluster_meta_manifest'}, but this value is unmatched
-riak_core_metadata_manager.erl:402: Expression produces a value of type 'ok' | {'error',_}, but this value is unmatched
-riak_core_metadata_manager.erl:560: Expression produces a value of type atom() | tid(), but this value is unmatched
-riak_core_metadata_manager.erl:599: Expression produces a value of type atom() | {'error',_} | tid(), but this value is unmatched

Verified nothing was missed for cluster meta related modules:

# egrep '(riak_core_(broadcast|metadata)|hashtree_tree)' d2.txt
Compiled src/riak_core_metadata_exchange_fsm.erl
Compiled src/riak_core_metadata_manager.erl
Compiled src/hashtree_tree.erl
Compiled src/riak_core_broadcast.erl

Still trying to run cluster_meta_basic, having issues with goldrush starting or something.

[rzezeski]

Successful run of cluster_meta_basic test. My problem before was bad
test setup.

Test Results:
cluster_meta_basic-bitcask: pass
---------------------------------------------
0 Tests Failed
1 Tests Passed
That's 100.0% for those keeping score

[rzezeski]

+1 to merge.