net: pktgen: don't abuse current->state in pktgen_thread_worker()

Commit 1fbe4b46caca "net: pktgen: kill the Wait for kthread_stop
code in pktgen_thread_worker()" removed (in particular) the final
__set_current_state(TASK_RUNNING) and I didn't notice the previous
set_current_state(TASK_INTERRUPTIBLE). This triggers the warning
in __might_sleep() after return.

Afaics, we can simply remove both set_current_state()'s, and we
could do this a long ago right after ef87979c273a2 "pktgen: better
scheduler friendliness" which changed pktgen_thread_worker() to
use wait_event_interruptible_timeout().

Reported-by: Huang Ying <ying.huang@intel.com>
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/core/pktgen.c

@@ -3514,8 +3514,6 @@ static int pktgen_thread_worker(void *arg)
 
 	set_freezable();
 
-	__set_current_state(TASK_RUNNING);
-
 	while (!kthread_should_stop()) {
 		pkt_dev = next_to_run(t);
 
@@ -3560,7 +3558,6 @@ static int pktgen_thread_worker(void *arg)
 
 		try_to_freeze();
 	}
-	set_current_state(TASK_INTERRUPTIBLE);
 
 	pr_debug("%s stopping all device\n", t->tsk->comm);
 	pktgen_stop(t);