media: i2c: mt9p031: fix mbus code initialization

The mediabus code is device dependent, but the probe() function
thought that device_get_match_data() would return the code directly,
when in fact it returned a pointer to a struct mt9p031_model_info.

As a result, the initial mbus code was garbage.

Tested with a BeagleBoard xM and a Leopard Imaging LI-5M03 sensor board.

Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Hans Verkuil <hverkuil+cisco@kernel.org>
Tested-by: Hans Verkuil <hverkuil+cisco@kernel.org>
Fixes: a80b1bbf ("media: mt9p031: Refactor format handling for different sensor models")
Cc: stable@vger.kernel.org