mm/list_lru.c: pass struct list_lru_node* as an argument to __list_lru_walk_one()

mm/list_lru.c: pass struct list_lru_node* as an argument to __list_lru_walk_one()

__list_lru_walk_one() is invoked with struct list_lru *lru, int nid as
the first two argument.  Those two are only used to retrieve struct
list_lru_node.  Since this is already done by the caller of the function
for the locking, we can pass struct list_lru_node* directly and avoid
the dance around it.

Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Sebastian Andrzej Siewior <[email protected]>
Reviewed-by: Vladimir Davydov <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>