cuse: kill connection on initialization error

Luca Risolia reported that a CUSE daemon will continue to run even if
initialization of the emulated device failes for some reason (e.g. the device
number is already registered by another driver).

This patch disconnects the fuse device on error, which will make the userspace
CUSE daemon exit, albeit without indication about what the problem was.

Reported-by: Luca Risolia <luca.risolia@studio.unibo.it>
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>

fs/fuse/cuse.c

@@ -396,7 +396,7 @@ err_device:
 err_region:
 	unregister_chrdev_region(devt, 1);
 err:
-	fc->conn_error = 1;
+	fuse_conn_kill(fc);
 	goto out;
 }
 
@@ -532,8 +532,6 @@ static int cuse_channel_release(struct inode *inode, struct file *file)
 		cdev_del(cc->cdev);
 	}
 
-	/* kill connection and shutdown channel */
-	fuse_conn_kill(&cc->fc);
 	rc = fuse_dev_release(inode, file);	/* puts the base reference */
 
 	return rc;