Add missing checks for geometry shader stages in GrVkUtil.cpp

Bug: skia:
Change-Id: I30cb6d5ee5016536537c48346c58ef4cf19f16c5
Reviewed-on: https://skia-review.googlesource.com/21845
Reviewed-by: Greg Daniel <egdaniel@google.com>
Commit-Queue: Chris Dalton <csmartdalton@google.com>
1 file changed