mm: fix filemap.c kernel-doc warnings

Fix kernel-doc warnings in mm/filemap.c:

  mm/filemap.c:993: warning: No description found for parameter '__page'
  mm/filemap.c:993: warning: Excess function parameter 'page' description in '__lock_page'

Link: http://lkml.kernel.org/r/a66fe492-518c-ad6c-5f03-5e8b721fb451@infradead.org
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm/filemap.c

@@ -1019,7 +1019,7 @@ EXPORT_SYMBOL_GPL(page_endio);
 
 /**
  * __lock_page - get a lock on the page, assuming we need to sleep to get it
- * @page: the page to lock
+ * @__page: the page to lock
  */
 void __lock_page(struct page *__page)
 {