GL: Fix usage of glGetInternalFormativ. The Target was being passed cube map faces for cube map textures. The return value is an enum, not a bool. BUG=angleproject:1932 Change-Id: I975f510fc0f6bc4d29adcbb152b0329ecbcdfa92 Reviewed-on: https://chromium-review.googlesource.com/902192 Reviewed-by: Corentin Wallez <cwallez@chromium.org> Commit-Queue: Geoff Lang <geofflang@chromium.org>