rm spurious std::move from getFontAtlasImage_ForTesting

Change-Id: I3a384126b01d6f066f70f6ef8e75bf3445f94daf
Reviewed-on: https://skia-review.googlesource.com/98706
Reviewed-by: Jim Van Verth <jvanverth@google.com>
Commit-Queue: Robert Phillips <robertphillips@google.com>
1 file changed