raid5-ppl: use BIOSET_NEED_BVECS when creating bioset

This bioset is used for allocating bios with nr_iovecs > 0 so this flag
must be set.

Fixes: 011067b0 ("blk: replace bioset_create_nobvec() with a flags arg to bioset_create()")
Signed-off-by: Artur Paszkiewicz <artur.paszkiewicz@intel.com>
Signed-off-by: Shaohua Li <shli@fb.com>

drivers/md/raid5-ppl.c

@@ -1150,7 +1150,7 @@ int ppl_init_log(struct r5conf *conf)
 		goto err;
 	}
 
-	ppl_conf->bs = bioset_create(conf->raid_disks, 0, 0);
+	ppl_conf->bs = bioset_create(conf->raid_disks, 0, BIOSET_NEED_BVECS);
 	if (!ppl_conf->bs) {
 		ret = -ENOMEM;
 		goto err;