Remove comments referencing locked pixels

Pixels no longer need to be locked.

TBR=reed@google.com

Bug: skia: 6481
Change-Id: I4b49f710add9134205d1520755b44bee308bd502
Reviewed-on: https://skia-review.googlesource.com/16113
Reviewed-by: Leon Scroggins <scroggo@google.com>
Reviewed-by: Mike Reed <reed@google.com>
Commit-Queue: Leon Scroggins <scroggo@google.com>
2 files changed