GL errors are generated during initialization on this device. Suppress
them until enough logging is in place to debug.

BUG=998503
BUG=angleproject:3020

Change-Id: I74a51a661a930ea89b0234dcb3e6213288e75c86
Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/1774468Reviewed-by: Corentin Wallez <cwallez@chromium.org>
Commit-Queue: Corentin Wallez <cwallez@chromium.org>