mm/page_alloc.c: remove redundant init code for ZONE_MOVABLE

arch_zone_lowest/highest_possible_pfn[] is set to 0 and [ZONE_MOVABLE]
is skipped in the loop.  No need to reset them to 0 again.

This patch just removes the redundant code.

Link: http://lkml.kernel.org/r/20170209141731.60208-1-richard.weiyang@gmail.comSigned-off-by: Wei Yang <richard.weiyang@gmail.com>
Cc: Anshuman Khandual <khandual@linux.vnet.ibm.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Michal Hocko <mhocko@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm/page_alloc.c

@@ -6489,8 +6489,6 @@ void __init free_area_init_nodes(unsigned long *max_zone_pfn)
 
 		start_pfn = end_pfn;
 	}
-	arch_zone_lowest_possible_pfn[ZONE_MOVABLE] = 0;
-	arch_zone_highest_possible_pfn[ZONE_MOVABLE] = 0;
 
 	/* Find the PFNs that ZONE_MOVABLE begins at in each node */
 	memset(zone_movable_pfn, 0, sizeof(zone_movable_pfn));