netxen: clean up firmware version checks

NX2031 firmware version will never be > 4.0.0, so replace
(adapter->fw_major < 4) checks with pci revision ID check.

Signed-off-by: Dhananjay Phadke <dhananjay@netxen.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/netxen/netxen_nic.h b/drivers/net/netxen/netxen_nic.h
index e017827..b58d0b2 100644
--- a/drivers/net/netxen/netxen_nic.h
+++ b/drivers/net/netxen/netxen_nic.h
@@ -1299,7 +1299,7 @@
 
 	nx_nic_intr_coalesce_t coal;
 
-	u32 fw_major;
+	u32 resv5;
 	u32 fw_version;
 	const struct firmware *fw;
 };