Use correct transfer offset for GL_HALF_FLOAT_OES

Another issue that came up when reenabling ES2 ANGLE contexts.

Change-Id: I6f7af6af0511384faf7bc63e699a8f6ea7a2ce92
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/293916
Commit-Queue: Brian Salomon <bsalomon@google.com>
Commit-Queue: Greg Daniel <egdaniel@google.com>
Auto-Submit: Brian Salomon <bsalomon@google.com>
Reviewed-by: Greg Daniel <egdaniel@google.com>
1 file changed