net: chelsio: cxgb4vf: Fix wrong function name in comments

Fixes the following W=1 kernel build warning(s):

 drivers/net/ethernet/chelsio/cxgb4vf/sge.c:966: warning: expecting prototype for check_ring_tx_db(). Prototype was for ring_tx_db() instead

Cc: Raju Rangoju <rajur@chelsio.com>
Signed-off-by: Yang Shen <shenyang39@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/chelsio/cxgb4vf/sge.c

@@ -954,7 +954,7 @@ static void write_sgl(const struct sk_buff *skb, struct sge_txq *tq,
 }
 
 /**
- *	check_ring_tx_db - check and potentially ring a TX queue's doorbell
+ *	ring_tx_db - check and potentially ring a TX queue's doorbell
  *	@adapter: the adapter
  *	@tq: the TX queue
  *	@n: number of new descriptors to give to HW