ibmvnic: Correct ibmvnic handling of device open/close

When closing the ibmvnic device we need to release the resources used
in communicating to the virtual I/O server. These need to be
re-negotiated with the server at open time.

This patch moves the releasing of resources a separate routine
and updates the open and close handlers to release all resources at
close and re-negotiate and allocate these resources at open.

Signed-off-by: Nathan Fontenot <nfont@linux.vnet.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/ibm/ibmvnic.h

@@ -1052,4 +1052,5 @@ struct ibmvnic_adapter {
 	struct work_struct ibmvnic_xport;
 	struct tasklet_struct tasklet;
 	bool failover;
+	bool is_closed;
 };