swapfile: let others seed random

Remove the srandom32((u32)get_seconds()) from non-rotational swapon:
there's been a coincidental discussion of earlier randomization, assume
that goes ahead, let swapon be a client rather than stirring for itself.
Signed-off-by: NHugh Dickins <hugh@veritas.com>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Donjun Shin <djshin90@gmail.com>
Cc: James Bottomley <James.Bottomley@HansenPartnership.com>
Cc: Jens Axboe <jens.axboe@oracle.com>
Cc: Joern Engel <joern@logfs.org>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Matthew Wilcox <matthew@wil.cx>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Cc: Tejun Heo <teheo@suse.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

mm/swapfile.c

@@ -1851,7 +1851,6 @@ asmlinkage long sys_swapon(const char __user * specialfile, int swap_flags)
 
 	if (blk_queue_nonrot(bdev_get_queue(p->bdev))) {
 		p->flags |= SWP_SOLIDSTATE;
-		srandom32((u32)get_seconds());
 		p->cluster_next = 1 + (random32() % p->highest_bit);
 	}
 	if (discard_swap(p) == 0)