dm-crypt: use unbound workqueue for request processing

Use unbound workqueue so that work is automatically ballanced between
available CPUs.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>

---
 drivers/md/dm-crypt.c |    3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

Index: linux-3.10.40/drivers/md/dm-crypt.c
===================================================================
--- linux-3.10.40.orig/drivers/md/dm-crypt.c	2014-06-03 22:28:50.000000000 +0200
+++ linux-3.10.40/drivers/md/dm-crypt.c	2014-06-03 22:28:58.000000000 +0200
@@ -1561,7 +1561,8 @@ static int crypt_ctr(struct dm_target *t
 	ret = -ENOMEM;
 	cc->io_queue = alloc_workqueue("kcryptd_io",
 				       WQ_NON_REENTRANT|
-				       WQ_MEM_RECLAIM,
+				       WQ_MEM_RECLAIM|
+				       WQ_UNBOUND,
 				       1);
 	if (!cc->io_queue) {
 		ti->error = "Couldn't create kcryptd io queue";