Make error messages end in a dot Some messages had dot and some not. Fix by adding dot to all error message string literals. Best effort, for free form string literals, check ANGLE_CHECK invocation sites only. Bug: angleproject:392938089 Change-Id: Idedc3fe1d1e186fb91b5e54407df87f6830995a0 Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/6218460 Reviewed-by: Geoff Lang <geofflang@chromium.org>