pipeline: make _GET_LAYER_NO_CREATE enum a flag
pipeline: make _GET_LAYER_NO_CREATE enum a flag

_cogl_pipeline_get_layer_with_flags accepts a CoglPipelineGetLayerFlags
flags argument and understands one COGL_PIPELINE_GET_LAYER_NO_CREATE
flag. There was a mistake with the definition of this enum though so
COGL_PIPELINE_GET_LAYER_NO_CREATE had a value of 0 and so testing for
the flag using the bitwise & operator would never find the flag set.

Reviewed-by: Neil Roberts <822ec91a7ef82248fd36162ca8ac3283eba70848@linux.intel.com>

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