stifle GCC warnings in Sk4px

GCC warngs that we're memcpy()ing into Sk4px, a non-trivial type.  We're
really quite sure about its layout (now asserted) so I think it's safe
to just cast to void* to quiet the warnings.

Change-Id: I6b868e0dc7113302914c37b0aac187272203329f
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/258270
Commit-Queue: Brian Salomon <bsalomon@google.com>
Reviewed-by: Brian Salomon <bsalomon@google.com>
Auto-Submit: Mike Klein <mtklein@google.com>
1 file changed