fix typo in SkJpegCodec.cpp

The missing break rejects grayscale profiles for grayscale images.

Change-Id: I16ad8e7b581f009257a47c4e0f45f7b3c0008487
Reviewed-on: https://skia-review.googlesource.com/66140
Reviewed-by: Mike Klein <mtklein@chromium.org>
Commit-Queue: Mike Klein <mtklein@chromium.org>
1 file changed