fix sk_colorspace include guard

Change-Id: Id6db4fd8147ac96d8fecab3b73d50c5098a070f8
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/209897
Reviewed-by: Mike Klein <mtklein@google.com>
Commit-Queue: Mike Klein <mtklein@google.com>
1 file changed