Fix GrTextureOp to check the correct cap for multitexturing

Change-Id: I276dff12055b046423ed261d014bc58302fb1347
Reviewed-on: https://skia-review.googlesource.com/70680
Reviewed-by: Robert Phillips <robertphillips@google.com>
Commit-Queue: Brian Salomon <bsalomon@google.com>
1 file changed