ixgbe: function comment typo

Seems the ixgbe's code was copied from e1000.
The comment talks about something not exist.
Signed-off-by: NWang Chen <wangchen@cn.fujitsu.com>
Acked-by: NJeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

drivers/net/ixgbe/ixgbe_main.c

@@ -2521,8 +2521,7 @@ static void ixgbe_cache_ring_register(struct ixgbe_adapter *adapter)
  * @adapter: board private structure to initialize
  *
  * We allocate one ring per queue at run-time since we don't know the
- * number of queues at compile-time.  The polling_netdev array is
- * intended for Multiqueue, but should work fine with a single queue.
+ * number of queues at compile-time.
  **/
 static int ixgbe_alloc_queues(struct ixgbe_adapter *adapter)
 {