media: i2c: ov8856: free control handler on error in ov8856_init_controls()

media: i2c: ov8856: free control handler on error in ov8856_init_controls()

The control handler wasn't freed if adding controls failed, add an error
exit label and convert the existing error return to use it.

Fixes: 879347f0c258 ("media: ov8856: Add support for OV8856 sensor")
Cc: stable@vger.kernel.org
Signed-off-by: Alexander Koskovich <akoskovich@pm.me>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Hans Verkuil <hverkuil+cisco@kernel.org>