net: tulip: Remove the repeated declaration

Function 'pnic2_lnk_change' is declared twice, so remove the
repeated declaration.

Cc: "David S. Miller" <davem@davemloft.net>
Cc: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Shaokun Zhang <zhangshaokun@hisilicon.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/dec/tulip/tulip.h

@@ -478,7 +478,6 @@ void t21142_lnk_change(struct net_device *dev, int csr5);
 void pnic2_lnk_change(struct net_device *dev, int csr5);
 void pnic2_timer(struct timer_list *t);
 void pnic2_start_nway(struct net_device *dev);
-void pnic2_lnk_change(struct net_device *dev, int csr5);
 
 /* eeprom.c */
 void tulip_parse_eeprom(struct net_device *dev);