hi846_init_controls doesn't clean the allocated ctrl_hdlr
in case there is a failure, which causes memleak. Add
v4l2_ctrl_handler_free to free the resource properly.

Fixes: e8c08826 ("media: i2c: add driver for the SK Hynix Hi-846 8M pixel camera")
Signed-off-by: Wei Chen <harperchen1110@gmail.com>
Reviewed-by: Martin Kepplinger <martin.kepplinger@puri.sm>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>