The original intent of the code was to allow both with and without .git
suffix for now to allow a transition period. The noVCSSuffix check was a
copy pasta error.

Fixes #15979.

Change-Id: I3d39aba8d026b40fc445244d6d01d8bc1979d1e4
Reviewed-on: https://go-review.googlesource.com/24645Reviewed-by: Ian Lance Taylor <iant@golang.org>