media: ov2685: Assign ret in default case in s_ctrl callback

Assign ret in the default case for s_ctrl callback. This can't happen but
still may result in compiler warnings.
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>

drivers/media/i2c/ov2685.c

@@ -574,6 +574,7 @@ static int ov2685_set_ctrl(struct v4l2_ctrl *ctrl)
 	default:
 		dev_warn(&client->dev, "%s Unhandled id:0x%x, val:0x%x\n",
 			 __func__, ctrl->id, ctrl->val);
+		ret = -EINVAL;
 		break;
 	};