mm: fix set pageblock migratetype in deferred struct page init

mm: fix set pageblock migratetype in deferred struct page init

On x86_64 MAX_ORDER_NR_PAGES is usually 4M, and a pageblock is usually 2M,
so we only set one pageblock's migratetype in deferred_free_range() if pfn
is aligned to MAX_ORDER_NR_PAGES.  That means it causes uninitialized
migratetype blocks, you can see from "cat /proc/pagetypeinfo", almost half
blocks are Unmovable.

Also we missed freeing the last block in deferred_init_memmap(), it causes
memory leak.

Fixes: ac5d2539b238 ("mm: meminit: reduce number of times pageblocks are set during struct page init")
Link: http://lkml.kernel.org/r/57A3260F.4050709@huawei.com
Signed-off-by: Xishi Qiu <qiuxishi@huawei.com>
Cc: Taku Izumi <izumi.taku@jp.fujitsu.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Michal Hocko <mhocko@suse.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: "Kirill A . Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Kamezawa Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>