index has been removed from __radix_tree_delete_node in 
449dd6984d0e47
("mm: keep page cache radix tree nodes in check")
Signed-off-by: Fabian Frederick <fabf@skynet.be>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
 
 /**
  *     __radix_tree_delete_node    -    try to free node after clearing a slot
  *     @root:          radix tree root
- *     @index:         index key
  *     @node:          node containing @index
  *
  *     After clearing the slot at @index in @node from radix tree