Vulkan: Make framebuffer fetch syncval errors more specific The errors are very generic, so now they are only suppressed if framebuffer fetch is used by the application. This change partially relands 2eeb87488. Bug: angleproject:6951 Change-Id: I55f444d19360d3066f1d4b0959d25e676dbb1a38 Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/3444341 Reviewed-by: Jamie Madill <jmadill@chromium.org> Reviewed-by: Ian Elliott <ianelliott@google.com> Commit-Queue: Shahbaz Youssefi <syoussefi@chromium.org>