tests/compose: Fix subtest scoping

We had a subtest that wasn't actually part of the `basic_test()` and so
was being executed when the file gets sourced instead of the function
being explicitly called.

Closes: #1829
Approved by: cgwalters

tests/compose-tests/libbasic-test.sh

@@ -100,8 +100,8 @@ assert_file_has_content pkglist.txt 'systemd'
 # also change the corresponding test in misc-tweaks.sh.
 assert_file_has_content pkglist.txt 'systemd-bootchart'
 echo "ok compose pkglist"
-}
 
 ostree --repo=${repobuild} cat ${treeref} /usr/share/rpm-ostree/treefile.json > treefile.json
 assert_jq treefile.json '.basearch == "x86_64"'
 echo "ok basearch"
+}