sched,timer: Use __set_current_state()

There's an existing helper for setting TASK_RUNNING; must've gotten
lost last time we did this cleanup.

Signed-off-by: Peter Zijlstra (Intel) <[e-mail]>
Reviewed-by: Davidlohr Bueso <[e-mail]>
Acked-by: Will Deacon <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]

kernel/time/timer.c

···
 			printk(KERN_ERR "schedule_timeout: wrong timeout "
 				"value %lx\n", timeout);
 			dump_stack();
-			current->state = TASK_RUNNING;
+			__set_current_state(TASK_RUNNING);
 			goto out;
 		}
 	}