[cogl] Flush matrix before clip planes
[cogl] Flush matrix before clip planes

glClipPlane() is affected by modelview matrix so we need to flush
before calling it.

Signed-off-by: Emmanuele Bassi <049ee2061f71220e5aaf33f5be422fc2a2b06a44@linux.intel.com>

Distrotech/cogl,Distrotech/cogl,djdeath/cogl,spatulasnout/cogl,djdeath/cogl-android,gcampax/cogl,spatulasnout/cogl,gcampax/cogl,collects/cogl,djdeath/cogl-android,gcampax/cogl,collects/cogl,djdeath/cogl,djdeath/cogl,gcampax/cogl,Distrotech/cogl,djdeath/cogl-android,Distrotech/cogl