dac960: return success instead of -ENOTTY

There is a missing break statement here.  This used to return directly
but we re-worked it in 2008 to add locking as part of the BKL push down.
Signed-off-by: NDan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

drivers/block/DAC960.c

@@ -7054,6 +7054,7 @@ static long DAC960_gam_ioctl(struct file *file, unsigned int Request,
 	else
 		ErrorCode =  0;
       }
+      break;
       default:
 	ErrorCode = -ENOTTY;
     }