[graphite] Fix invalid assert condition in GraphiteResourceKey

If keys aren't equal, there's no requirement that their shareability
be the same. It's only if they are otherwise equal that their
shareability match.

Change-Id: I2794b1c7cf84c6d9670746b32f6381f520275db0
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/856031
Reviewed-by: Robert Phillips <robertphillips@google.com>
Commit-Queue: Michael Ludwig <michaelludwig@google.com>
Auto-Submit: Michael Ludwig <michaelludwig@google.com>
Commit-Queue: Robert Phillips <robertphillips@google.com>
1 file changed