new helper: file_inode(file)

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/fs/udf/dir.c b/fs/udf/dir.c
index eb8bfe2..b3e93f5 100644
--- a/fs/udf/dir.c
+++ b/fs/udf/dir.c
@@ -186,7 +186,7 @@
 
 static int udf_readdir(struct file *filp, void *dirent, filldir_t filldir)
 {
-	struct inode *dir = filp->f_path.dentry->d_inode;
+	struct inode *dir = file_inode(filp);
 	int result;
 
 	if (filp->f_pos == 0) {