sockfs: switch to ->free_inode()

we do have an RCU-delayed part there already (freeing the wq),
so it's not like the pipe situation; moreover, it might be
worth considering coallocating wq with the rest of struct sock_alloc.
->sk_wq in struct sock would remain a pointer as it is, but
the object it normally points to would be coallocated with
struct socket...
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/socket.c

@@ -258,12 +258,12 @@ static struct inode *sock_alloc_inode(struct super_block *sb)
 	return &ei->vfs_inode;
 }
 
-static void sock_destroy_inode(struct inode *inode)
+static void sock_free_inode(struct inode *inode)
 {
 	struct socket_alloc *ei;
 
 	ei = container_of(inode, struct socket_alloc, vfs_inode);
-	kfree_rcu(ei->socket.wq, rcu);
+	kfree(ei->socket.wq);
 	kmem_cache_free(sock_inode_cachep, ei);
 }
 
@@ -288,7 +288,7 @@ static void init_inodecache(void)
 
 static const struct super_operations sockfs_ops = {
 	.alloc_inode	= sock_alloc_inode,
-	.destroy_inode	= sock_destroy_inode,
+	.free_inode	= sock_free_inode,
 	.statfs		= simple_statfs,
 };