fix typo

kernel/sched/pb.c

@@ -194,7 +194,7 @@ static struct task_struct * pick_next_task_pb(struct rq *rq,
 
 	/**
 	 * This handles the case where the program to be run is dead before the
-	 * pb scheduler starting executing
+	 * pb scheduler starts executing
 	 */
 	if (current_mode == PB_DISABLED_MODE && current_mode != next_mode) {
 		if (pb->c_entry < pb->size && pb->plan[pb->c_entry].task_struct->state == TASK_DEAD) {