No need to manually remove tmp directory created by t.TempDir()

[ahrtr]

The temporary directory created by t.TempDir() can be automatically removed by
the golang testing utilities. So no need to remove it manually.

FYI.

• https://github.com/golang/go/blob/go1.16.15/src/testing/testing.go#L911-L915
• https://github.com/golang/go/blob/go1.16.15/src/testing/testing.go#L957

Signed-off-by: Benjamin Wang wachao@vmware.com

Please read https://github.com/etcd-io/etcd/blob/main/CONTRIBUTING.md#contribution-flow.

[codecov-commenter]

Codecov Report

Merging #14248 (f6cfd46) into main (b75aa3e) will decrease coverage by 0.20%.
The diff coverage is n/a.

@@            Coverage Diff             @@
##             main   #14248      +/-   ##
==========================================
- Coverage   75.42%   75.22%   -0.21%     
==========================================
  Files         456      456              
  Lines       36919    36919              
==========================================
- Hits        27847    27772      -75     
- Misses       7340     7404      +64     
- Partials     1732     1743      +11     

Flag	Coverage Δ
all	75.22% <ø> (-0.21%)	⬇️

Flags with carried forward coverage won't be shown. Click here to find out more.

Impacted Files	Coverage Δ
server/proxy/grpcproxy/register.go	69.76% <0.00%> (-9.31%)	⬇️
client/pkg/v3/tlsutil/tlsutil.go	83.33% <0.00%> (-8.34%)	⬇️
client/v3/experimental/recipes/queue.go	58.62% <0.00%> (-6.90%)	⬇️
client/v3/namespace/watch.go	87.87% <0.00%> (-6.07%)	⬇️
server/storage/mvcc/watchable_store.go	84.42% <0.00%> (-4.72%)	⬇️
client/v3/concurrency/session.go	88.63% <0.00%> (-4.55%)	⬇️
server/etcdserver/cluster_util.go	70.35% <0.00%> (-3.17%)	⬇️
server/etcdserver/api/v3rpc/interceptor.go	74.47% <0.00%> (-3.13%)	⬇️
client/v3/experimental/recipes/double_barrier.go	71.87% <0.00%> (-3.13%)	⬇️
client/v3/retry_interceptor.go	64.54% <0.00%> (-2.73%)	⬇️
... and 16 more