mm, page_alloc: inline pageblock lookup in page free fast paths

The function call overhead of get_pfnblock_flags_mask() is measurable in
the page free paths.  This patch uses an inlined version that is faster.

Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/mm/vmstat.c b/mm/vmstat.c
index f1a73bf..5b72a8a 100644
--- a/mm/vmstat.c
+++ b/mm/vmstat.c
@@ -1041,7 +1041,7 @@
 		block_end_pfn = min(block_end_pfn, end_pfn);
 
 		page = pfn_to_page(pfn);
-		pageblock_mt = get_pfnblock_migratetype(page, pfn);
+		pageblock_mt = get_pageblock_migratetype(page);
 
 		for (; pfn < block_end_pfn; pfn++) {
 			if (!pfn_valid_within(pfn))