filemap: fix kernel-doc warnings

Fix filemap.c kernel-doc warnings:

Warning(mm/filemap.c:575): No description found for parameter 'page'
Warning(mm/filemap.c:575): No description found for parameter 'waiter'
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm/filemap.c

@@ -567,8 +567,8 @@ EXPORT_SYMBOL(wait_on_page_bit);
 
 /**
  * add_page_wait_queue - Add an arbitrary waiter to a page's wait queue
- * @page - Page defining the wait queue of interest
- * @waiter - Waiter to add to the queue
+ * @page: Page defining the wait queue of interest
+ * @waiter: Waiter to add to the queue
  *
  * Add an arbitrary @waiter to the wait queue for the nominated @page.
  */