Fix extension suffic for getting procs from GL_EXT_debug_marker on ES

Change-Id: I483fbf7c5f6d4489802def78fa855f70313e4a19
Reviewed-on: https://skia-review.googlesource.com/7602
Reviewed-by: Greg Daniel <egdaniel@google.com>
Commit-Queue: Brian Salomon <bsalomon@google.com>
1 file changed