fix: close file in error handling

[testwill]

No description provided.

[machine424]

Thanks.
I'd be great to mention that in the function doc comments for better visibility.

And I think we should get rid of the cleanup code here

prometheus/promql/query_logger_test.go

Lines 114 to 116 in f36915b

	if err != nil {
	t.Cleanup(func() { closer.Close() })
	}

as the fct should take care of that now.

[machine424]

Thanks!

[aknuds1]

I don't understand why not close the returned Closer in TestMMapFile.

[aknuds1]

LGTM, thanks!