ceph: num_ops is off by one in ceph_aio_retry_work()

Two OSD op slots are allocated, but only one is ever used.
Signed-off-by: NIlya Dryomov <idryomov@gmail.com>

fs/ceph/file.c

@@ -858,7 +858,7 @@ static void ceph_aio_retry_work(struct work_struct *work)
 	}
 	spin_unlock(&ci->i_ceph_lock);
 
-	req = ceph_osdc_alloc_request(orig_req->r_osdc, snapc, 2,
+	req = ceph_osdc_alloc_request(orig_req->r_osdc, snapc, 1,
 			false, GFP_NOFS);
 	if (!req) {
 		ret = -ENOMEM;