Vulkan: Skip releaseImage call when image is invalid releaseImage is only useful if image is already valid. Otherwise it is wasting CPU cycles to go through bunch of release calls that essentially doing nothing. Bug: angleproject:6014 Change-Id: I550b12bdc566cca699f6bf6662d176a01b2bce2e Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/3183800 Commit-Queue: Charlie Lao <cclao@google.com> Reviewed-by: Shahbaz Youssefi <syoussefi@chromium.org> Reviewed-by: Jamie Madill <jmadill@chromium.org> Reviewed-by: Tim Van Patten <timvp@google.com>