sched/sched/sched.h: Make naming of all internal names consistent:

1. Add internal scheduler functions should begin with nxsched_, not sched_
2. Follow the consistent naming patter of https://cwiki.apache.org/confluence/display/NUTTX/Naming+of+OS+Internal+Functions

arch/z80/src/common/z80_blocktask.c

@@ -77,11 +77,11 @@ void up_block_task(FAR struct tcb_s *tcb, tstate_t task_state)
    * it should also be true that rtcb == tcb.
    */
 
-  switch_needed = sched_removereadytorun(tcb);
+  switch_needed = nxsched_remove_readytorun(tcb);
 
   /* Add the task to the specified blocked task list */
 
-  sched_addblocked(tcb, (tstate_t)task_state);
+  nxsched_add_blocked(tcb, (tstate_t)task_state);
 
   /* If there are any pending tasks, then add them to the ready-to-run
    * task list now
@@ -89,7 +89,7 @@ void up_block_task(FAR struct tcb_s *tcb, tstate_t task_state)
 
   if (g_pendingtasks.head)
     {
-      switch_needed |= sched_mergepending();
+      switch_needed |= nxsched_merge_pending();
     }
 
   /* Now, perform the context switch if one is needed */

arch/z80/src/common/z80_releasepending.c

@@ -59,7 +59,7 @@ void up_release_pending(void)
 
   /* Merge the g_pendingtasks list into the ready-to-run task list */
 
-  if (sched_mergepending())
+  if (nxsched_merge_pending())
     {
       /* The currently active task has changed!  We will need to switch
        * contexts.

arch/z80/src/common/z80_reprioritizertr.c

@@ -86,25 +86,25 @@ void up_reprioritize_rtr(FAR struct tcb_s *tcb, uint8_t priority)
       sinfo("TCB=%p PRI=%d\n", tcb, priority);
 
       /* Remove the tcb task from the ready-to-run list.
-       * sched_removereadytorun will return true if we just
+       * nxsched_remove_readytorun will return true if we just
        * remove the head of the ready to run list.
        */
 
-      switch_needed = sched_removereadytorun(tcb);
+      switch_needed = nxsched_remove_readytorun(tcb);
 
       /* Setup up the new task priority */
 
       tcb->sched_priority = (uint8_t)priority;
 
       /* Return the task to the specified blocked task list.
-       * sched_addreadytorun will return true if the task was
+       * nxsched_add_readytorun will return true if the task was
        * added to the new list.  We will need to perform a context
        * switch only if the EXCLUSIVE or of the two calls is non-zero
        * (i.e., one and only one the calls changes the head of the
        * ready-to-run list).
        */
 
-      switch_needed ^= sched_addreadytorun(tcb);
+      switch_needed ^= nxsched_add_readytorun(tcb);
 
       /* Now, perform the context switch if one is needed */
 
@@ -117,7 +117,7 @@ void up_reprioritize_rtr(FAR struct tcb_s *tcb, uint8_t priority)
 
           if (g_pendingtasks.head)
             {
-              sched_mergepending();
+              nxsched_merge_pending();
             }
 
           /* Update scheduler parameters */

arch/z80/src/common/z80_unblocktask.c

@@ -70,13 +70,13 @@ void up_unblock_task(FAR struct tcb_s *tcb)
 
   /* Remove the task from the blocked task list */
 
-  sched_removeblocked(tcb);
+  nxsched_remove_blocked(tcb);
 
   /* Add the task in the correct location in the prioritized
    * ready-to-run task list
    */
 
-  if (sched_addreadytorun(tcb))
+  if (nxsched_add_readytorun(tcb))
     {
       /* The currently active task has changed! We need to do
        * a context switch to the new task.