Fix a typo in _cogl_matrix_init_translation
Fix a typo in _cogl_matrix_init_translation

The y translation was being initialised with the z value and the z
translation was being left as 0.0.

djdeath/cogl-android,djdeath/cogl,gcampax/cogl,djdeath/cogl-android,gcampax/cogl,gcampax/cogl,djdeath/cogl,djdeath/cogl,djdeath/cogl-android,gcampax/cogl