net/vhost-user: Remove unused "err" from net_vhost_user_event() (CID 1612372)

The "err" variable was declared but never used within the
net_vhost_user_event() function. This resulted in a dead code
warning (CID 1612372) from Coverity.

Remove the unused variable and the associated error block
to resolve the issue.

Signed-off-by: Laurent Vivier <lvivier@redhat.com>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Jason Wang <jasowang@redhat.com>

net/vhost-user.c

@@ -329,7 +329,6 @@ static void net_vhost_user_event(void *opaque, QEMUChrEvent event)
     NetClientState *ncs[MAX_QUEUE_NUM];
     NetVhostUserState *s;
     Chardev *chr;
-    Error *err = NULL;
     int queues;
 
     queues = qemu_find_net_clients_except(name, ncs,
@@ -375,10 +374,6 @@ static void net_vhost_user_event(void *opaque, QEMUChrEvent event)
         /* Ignore */
         break;
     }
-
-    if (err) {
-        error_report_err(err);
-    }
 }
 
 static int net_vhost_user_init(NetClientState *peer, const char *device,