Fix the condition of glOrtho{fx} validation According to the OpenGL ES 1.1 spec, remove the conditions of glOrtho validation that n and f must be positive. Bug: angleproject:4281 Change-Id: I644a25408a026ce87211f2203b8e8203eeaf69bd Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/2067002 Reviewed-by: Shahbaz Youssefi <syoussefi@chromium.org> Reviewed-by: Jamie Madill <jmadill@chromium.org> Commit-Queue: Jamie Madill <jmadill@chromium.org>