Vulkan: Minor fix when waitFor*ToBeSubmitted() may skip error. Calling "checkAndPopPendingError()" without "mSubmissionMutex" lock may cause situation, when new error is added to "mErrors" right after the call. This new error may be for the work we are waiting for, and it processing will be skipped. Current CommandProcessor error handing should be rewritten in the future anyway, but I think this minor error should be addressed now. Bug: b/267348918 Change-Id: I65c49f7dc8e1984696d464c38f13fcdce93337bf Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/4245421 Reviewed-by: Charlie Lao <cclao@google.com> Reviewed-by: Shahbaz Youssefi <syoussefi@chromium.org> Commit-Queue: Igor Nazarov <i.nazarov@samsung.com>