[PKTGEN]: Remove write-only variable.

The pktgen_thread.pid is set to current->pid and is never used
after this. So remove this at all.

Found during isolating the explicit pid/tgid usage.
Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Acked-by: Sukadev Bhattiprolu <sukadev@us.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/core/pktgen.c

@@ -380,7 +380,6 @@ struct pktgen_thread {
 	/* Field for thread to receive "posted" events terminate, stop ifs etc. */
 
 	u32 control;
-	int pid;
 	int cpu;
 
 	wait_queue_head_t queue;
@@ -3463,8 +3462,6 @@ static int pktgen_thread_worker(void *arg)
 
 	init_waitqueue_head(&t->queue);
 
-	t->pid = current->pid;
-
 	pr_debug("pktgen: starting pktgen/%d:  pid=%d\n", cpu, current->pid);
 
 	max_before_softirq = t->max_before_softirq;