go/packages: fix mistake for ad-hoc packages
go/packages: fix mistake for ad-hoc packages

Change-Id: I6247e0392a43cf4c4f4ded8446e045dfcd8e423d
Reviewed-on: https://go-review.googlesource.com/c/tools/+/183620
Run-TryBot: Rebecca Stambler <d7cf11e5f299d88ea8348366a9fc4f7c335c3afa@golang.org>
Run-TryBot: Michael Matloob <4562438b12c14e81a47550acde616ff328a909f8@golang.org>
Reviewed-by: Michael Matloob <4562438b12c14e81a47550acde616ff328a909f8@golang.org>

golang/tools,golang/tools,golang/tools,golang/tools,golang/tools