drivers/net: fix comparisons of unsigned < 0

Recent gcc versions emit warnings when unsigned variables are compared < 0 or >= 0.

Signed-off-by: Bill Nottingham <notting@redhat.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
diff --git a/drivers/net/netxen/netxen_nic_niu.c b/drivers/net/netxen/netxen_nic_niu.c
index 75102d3..05e0577 100644
--- a/drivers/net/netxen/netxen_nic_niu.c
+++ b/drivers/net/netxen/netxen_nic_niu.c
@@ -724,7 +724,7 @@
 	__u32 mac_cfg0;
 	u32 port = physical_port[adapter->portnum];
 
-	if ((port < 0) || (port > NETXEN_NIU_MAX_GBE_PORTS))
+	if (port > NETXEN_NIU_MAX_GBE_PORTS)
 		return -EINVAL;
 	mac_cfg0 = 0;
 	netxen_gb_soft_reset(mac_cfg0);
@@ -757,7 +757,7 @@
 	__u32 reg;
 	u32 port = physical_port[adapter->portnum];
 
-	if ((port < 0) || (port > NETXEN_NIU_MAX_GBE_PORTS))
+	if (port > NETXEN_NIU_MAX_GBE_PORTS)
 		return -EINVAL;
 
 	/* save previous contents */
@@ -894,7 +894,7 @@
 	__u32 reg;
 	u32 port = physical_port[adapter->portnum];
 
-	if ((port < 0) || (port > NETXEN_NIU_MAX_XG_PORTS))
+	if (port > NETXEN_NIU_MAX_XG_PORTS)
 		return -EINVAL;
 
 	if (netxen_nic_hw_read_wx(adapter,