sched: clear waitsem and msgwaitq after remove blocked

sched/mqueue/mq_rcvinternal.c

@@ -303,7 +303,6 @@ ssize_t nxmq_do_receive(FAR struct mqueue_inode_s *msgq,
           wd_cancel(&btcb->waitdog);
         }
 
-      btcb->waitobj = NULL;
       msgq->nwaitnotfull--;
       up_unblock_task(btcb);
     }

sched/mqueue/mq_sndinternal.c

@@ -410,7 +410,6 @@ int nxmq_do_send(FAR struct mqueue_inode_s *msgq,
           wd_cancel(&btcb->waitdog);
         }
 
-      btcb->waitobj = NULL;
       msgq->nwaitnotempty--;
       up_unblock_task(btcb);
     }

sched/mqueue/mq_waitirq.c

@@ -83,8 +83,6 @@ void nxmq_wait_irq(FAR struct tcb_s *wtcb, int errcode)
       msgq = wtcb->waitobj;
       DEBUGASSERT(msgq);
 
-      wtcb->waitobj = NULL;
-
       /* Decrement the count of waiters and cancel the wait */
 
       if (wtcb->task_state == TSTATE_WAIT_MQNOTEMPTY)

sched/sched/sched_removeblocked.c

@@ -67,6 +67,10 @@ void nxsched_remove_blocked(FAR struct tcb_s *btcb)
 
   dq_rem((FAR dq_entry_t *)btcb, TLIST_BLOCKED(task_state));
 
+  /* Indicate that the wait is over. */
+
+  btcb->waitobj = NULL;
+
   /* Make sure the TCB's state corresponds to not being in
    * any list
    */

sched/semaphore/sem_post.c

@@ -155,10 +155,6 @@ int nxsem_post(FAR sem_t *sem)
 
               wd_cancel(&stcb->waitdog);
 
-              /* It is, let the task take the semaphore */
-
-              stcb->waitobj = NULL;
-
               /* Restart the waiting task. */
 
               up_unblock_task(stcb);

sched/semaphore/sem_waitirq.c

@@ -97,10 +97,6 @@ void nxsem_wait_irq(FAR struct tcb_s *wtcb, int errcode)
 
       sem->semcount++;
 
-      /* Indicate that the semaphore wait is over. */
-
-      wtcb->waitobj = NULL;
-
       /* Mark the errno value for the thread. */
 
       wtcb->errcode = errcode;