Remove some unused vars from skqp

Change-Id: I5c3d04c17628f46c01814db6eead0337ebe68e16
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/500276
Commit-Queue: Florin Malita <fmalita@chromium.org>
Auto-Submit: Florin Malita <fmalita@chromium.org>
Reviewed-by: Derek Sollenberger <djsollen@google.com>
Commit-Queue: Derek Sollenberger <djsollen@google.com>
1 file changed