lockdep: fixup checking of dir inode annotation

Since inode->i_mode shares its bits for S_IFMT, S_ISDIR should be
used to distinguish whether it is a dir or not.
Signed-off-by: Namhyung Kim <namhyung@gmail.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

fs/inode.c

@@ -663,7 +663,7 @@ EXPORT_SYMBOL(new_inode);
 void unlock_new_inode(struct inode *inode)
 {
 #ifdef CONFIG_DEBUG_LOCK_ALLOC
-	if (inode->i_mode & S_IFDIR) {
+	if (S_ISDIR(inode->i_mode)) {
 		struct file_system_type *type = inode->i_sb->s_type;
 
 		/* Set new key only if filesystem hasn't already changed it */