staging: unisys: visornic - correctly reset flag prior to send_enbdis()

Because devdata->enab_dis_acked is the flag used to determine whether an
enable/disable operation to the IO partition has completed, it should
always be cleared prior to initiating the operation.  The call added to
visornic_enable_with_timeout() added in this patch makes the usage there
consistent with visornic_disable_with_timeout().
Signed-off-by: NTim Sell <Timothy.Sell@unisys.com>
Signed-off-by: NBenjamin Romer <benjamin.romer@unisys.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/unisys/visornic/visornic_main.c

@@ -680,6 +680,7 @@ visornic_enable_with_timeout(struct net_device *netdev, const int timeout)
 
 	spin_lock_irqsave(&devdata->priv_lock, flags);
 	devdata->enabled = 1;
+	devdata->enab_dis_acked = 0;
 
 	/* now we're ready, let's send an ENB to uisnic but until we get
 	 * an ACK back from uisnic, we'll drop the packets