mm: drop unneeded pgdat argument from free_area_init_node()

free_area_init_node() gets passed in the node id as well as the node
descriptor.  This is redundant as the function can trivially get the node
descriptor itself by means of NODE_DATA() and the node's id.

I checked all the users and NODE_DATA() seems to be usable everywhere
from where this function is called.

Signed-off-by: Johannes Weiner <hannes@saeurebad.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

arch/parisc/mm/init.c

@@ -887,7 +887,7 @@ void __init paging_init(void)
 		}
 #endif
 
-		free_area_init_node(i, NODE_DATA(i), zones_size,
+		free_area_init_node(i, zones_size,
 				pmem_ranges[i].start_pfn, NULL);
 	}
 }