netxen: cache msi register offset

Store msi target status register offset in adapter struct.
This avoids contention on msi_tgt_status table from interrupt
hadlers of different pci function.

Signed-off-by: Dhananjay Phadke <dhananjay@netxen.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/netxen/netxen_nic.h

@@ -1257,6 +1257,9 @@ struct netxen_adapter {
 	u32 irq;
 	u32 temp;
 
+	u32 msi_tgt_status;
+	u32 resv4;
+
 	struct netxen_adapter_stats stats;
 
 	struct netxen_recv_context recv_ctx;