new helper: file_inode(file)

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/net/unix/garbage.c b/net/unix/garbage.c
index b6f4b99..d0f6545 100644
--- a/net/unix/garbage.c
+++ b/net/unix/garbage.c
@@ -99,7 +99,7 @@
 struct sock *unix_get_socket(struct file *filp)
 {
 	struct sock *u_sock = NULL;
-	struct inode *inode = filp->f_path.dentry->d_inode;
+	struct inode *inode = file_inode(filp);
 
 	/*
 	 *	Socket ?