Fix "implicit conversion from 'int' to 'float' may lose precision"

Newer clang includes this warning, so add a bunch of explicit casts.

Change-Id: Ia315054ffd2168e32575c07855e6f6ddea27770a
Reviewed-on: https://skia-review.googlesource.com/c/skcms/+/542619
Commit-Queue: Brian Osman <brianosman@google.com>
Reviewed-by: Michael Ludwig <michaelludwig@google.com>
4 files changed