kill f_dentry uses

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/fs/ecryptfs/crypto.c b/fs/ecryptfs/crypto.c
index 2f6735d..c2d6604 100644
--- a/fs/ecryptfs/crypto.c
+++ b/fs/ecryptfs/crypto.c
@@ -1373,7 +1373,7 @@
 int ecryptfs_read_xattr_region(char *page_virt, struct inode *ecryptfs_inode)
 {
 	struct dentry *lower_dentry =
-		ecryptfs_inode_to_private(ecryptfs_inode)->lower_file->f_dentry;
+		ecryptfs_inode_to_private(ecryptfs_inode)->lower_file->f_path.dentry;
 	ssize_t size;
 	int rc = 0;