ext2: Fix some kernel-doc warnings

The current code provokes some kernel-doc warnings:
fs/ext2/dir.c:417: warning: This comment starts with '/**', but isn't a kernel-doc comment. Refer Documentation/doc-guide/kernel-doc.rst
Signed-off-by: NBo Liu <liubo03@inspur.com>
Acked-by: NRandy Dunlap <rdunlap@infradead.org>
Signed-off-by: NJan Kara <jack@suse.cz>

fs/ext2/dir.c

@@ -413,7 +413,7 @@ struct ext2_dir_entry_2 *ext2_find_entry (struct inode *dir,
 	return de;
 }
 
-/**
+/*
  * Return the '..' directory entry and the page in which the entry was found
  * (as a parameter - p).
  *