vrend: Do not try to swizzle vertex array on ES
requested to merge akihiko.odaki/virglrenderer:vrend-do-not-try-to-swizzle-vertex-array-on-es into master
glVertexAttribPointer on OpenGL ES does not accept GL_BGRA, which is necessary to swizzle vertex array.
Signed-off-by: Akihiko Odaki akihiko.odaki@gmail.com