staging: unisys: visornic: prevent hang doing 'modprobe -r visornic'

A stray+extraneous 'netif_napi_add()' that we were doing in
visornic_probe() was causing havoc when we got into visornic_remove(),
called during 'modprobe -r visornic'. The symptom was a processor busy-wait
loop on the modprobe process, which '/proc/<pid>/stack' would show looping
doing napi things.

Presumably the stray line got there as a result of some merging snafoo, and
has been deleted to fix the problem. With this patch 'modprobe -r visornic'
and a subsequent 'modprobe visornic' both complete successfully, and result
in an operational network.

Signed-off-by: Tim Sell <Timothy.Sell@unisys.com>
Signed-off-by: David Kershner <david.kershner@unisys.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/unisys/visornic/visornic_main.c

@@ -1802,7 +1802,7 @@ static int visornic_probe(struct visor_device *dev)
 
 	/* TODO: Setup Interrupt information */
 	/* Let's start our threads to get responses */
-	netif_napi_add(netdev, &devdata->napi, visornic_poll, 64);
+	netif_napi_add(netdev, &devdata->napi, visornic_poll, NAPI_WEIGHT);
 
 	setup_timer(&devdata->irq_poll_timer, poll_for_irq,
 		    (unsigned long)devdata);
@@ -1832,9 +1832,6 @@ static int visornic_probe(struct visor_device *dev)
 		goto cleanup_napi_add;
 	}
 
-	/* Let's start our threads to get responses */
-	netif_napi_add(netdev, &devdata->napi, visornic_poll, NAPI_WEIGHT);
-
 	/* Note: Interrupts have to be enable before the while
 	 * loop below because the napi routine is responsible for
 	 * setting enab_dis_acked