This also fixes a missed VkResult error. In order to do this
we also return an error from ProgramImpl::destroy.

Bug: angleproject:2396
Change-Id: I649b19e64732785bb33eebadea7f361245137d0f
Reviewed-on: https://chromium-review.googlesource.com/958406Reviewed-by: Jamie Madill <jmadill@chromium.org>
Commit-Queue: Jamie Madill <jmadill@chromium.org>