bnx2x: Correct PFC disablement

bnx2x driver could only have enabled pfc via usage of dcbnl; now, it can
also correctly disable it.
Signed-off-by: Barak Witkowski <barak@broadcom.com>
Signed-off-by: Yuval Mintz <yuvalmin@broadcom.com>
Signed-off-by: Eilon Greenstein <eilong@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/broadcom/bnx2x/bnx2x_dcb.c

@@ -2052,10 +2052,13 @@ static void bnx2x_dcbnl_set_pfc_cfg(struct net_device *netdev, int prio,
 	if (!bnx2x_dcbnl_set_valid(bp) || prio >= MAX_PFC_PRIORITIES)
 		return;
 
-	bp->dcbx_config_params.admin_pfc_bitmap |= ((setting ? 1 : 0) << prio);
 
-	if (setting)
+	if (setting) {
+		bp->dcbx_config_params.admin_pfc_bitmap |= (1 << prio);
 		bp->dcbx_config_params.admin_pfc_tx_enable = 1;
+	} else {
+		bp->dcbx_config_params.admin_pfc_bitmap &= ~(1 << prio);
+	}
 }
 
 static void bnx2x_dcbnl_get_pfc_cfg(struct net_device *netdev, int prio,