drbd: Fix state change in case of connection timeout

A connection timeout affects all volumes of a resource!
Under the following conditions:

 A resource with multiple volumes
  AND
 ko-count >=1
  AND
 a write request triggers the timeout (ko-count * timeout)

DRBD's internal state gets confused. That in turn may
lead to very miss leading follow up failures. E.g.
"BUG: scheduling while atomic"

CC: stable@kernel.org # v3.17
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
Signed-off-by: Jens Axboe <axboe@fb.com>

drivers/block/drbd/drbd_req.c

@@ -1629,7 +1629,7 @@ void request_timer_fn(unsigned long data)
 		 time_after(now, req_peer->pre_send_jif + ent) &&
 		!time_in_range(now, connection->last_reconnect_jif, connection->last_reconnect_jif + ent)) {
 		drbd_warn(device, "Remote failed to finish a request within ko-count * timeout\n");
-		_drbd_set_state(_NS(device, conn, C_TIMEOUT), CS_VERBOSE | CS_HARD, NULL);
+		_conn_request_state(connection, NS(conn, C_TIMEOUT), CS_VERBOSE | CS_HARD);
 	}
 	if (dt && oldest_submit_jif != now &&
 		 time_after(now, oldest_submit_jif + dt) &&