new helper: file_inode(file)

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/net/netlink/af_netlink.c b/net/netlink/af_netlink.c
index c0353d5..c1ee3a8 100644
--- a/net/netlink/af_netlink.c
+++ b/net/netlink/af_netlink.c
@@ -809,7 +809,7 @@
 
 struct sock *netlink_getsockbyfilp(struct file *filp)
 {
-	struct inode *inode = filp->f_path.dentry->d_inode;
+	struct inode *inode = file_inode(filp);
 	struct sock *sock;
 
 	if (!S_ISSOCK(inode->i_mode))