mm, nobootmem: do memset() after memblock_reserve()

Currently, we do memset() before reserving the area.  This may not cause
any problem, but it is somewhat weird.  So change execution order.

Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Yinghai Lu <yinghai@kernel.org>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Jiang Liu <liuj97@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/mm/nobootmem.c b/mm/nobootmem.c
index a31be7a..bdd3fa2 100644
--- a/mm/nobootmem.c
+++ b/mm/nobootmem.c
@@ -45,9 +45,9 @@
 	if (!addr)
 		return NULL;
 
+	memblock_reserve(addr, size);
 	ptr = phys_to_virt(addr);
 	memset(ptr, 0, size);
-	memblock_reserve(addr, size);
 	/*
 	 * The min_count is set to 0 so that bootmem allocated blocks
 	 * are never reported as leaks.