afs: Make dynamic root population wait uninterruptibly for proc_cells_lock

Make dynamic root population wait uninterruptibly for proc_cells_lock.
Signed-off-by: NDavid Howells <dhowells@redhat.com>

fs/afs/dynroot.c

@@ -261,8 +261,7 @@ int afs_dynroot_populate(struct super_block *sb)
 	struct afs_net *net = afs_sb2net(sb);
 	int ret;
 
-	if (mutex_lock_interruptible(&net->proc_cells_lock) < 0)
-		return -ERESTARTSYS;
+	mutex_lock(&net->proc_cells_lock);
 
 	net->dynroot_sb = sb;
 	hlist_for_each_entry(cell, &net->proc_cells, proc_link) {