mm/: rename random32() to prandom_u32()

Use preferable function name which implies using a pseudo-random
number generator.

Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/mm/swapfile.c b/mm/swapfile.c
index a1f7772..d417efd 100644
--- a/mm/swapfile.c
+++ b/mm/swapfile.c
@@ -2120,7 +2120,7 @@
 	if (p->bdev) {
 		if (blk_queue_nonrot(bdev_get_queue(p->bdev))) {
 			p->flags |= SWP_SOLIDSTATE;
-			p->cluster_next = 1 + (random32() % p->highest_bit);
+			p->cluster_next = 1 + (prandom_u32() % p->highest_bit);
 		}
 		if ((swap_flags & SWAP_FLAG_DISCARD) && discard_swap(p) == 0)
 			p->flags |= SWP_DISCARDABLE;