Clean up some boilerplate in runtimeshader.cpp

Change-Id: I068f71d94d506213e6c9b24d7fe5c6d6187e5ac0
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/302902
Reviewed-by: Brian Osman <brianosman@google.com>
Commit-Queue: Brian Osman <brianosman@google.com>
1 file changed