sched/sched: Fix some typos in comments.

Signed-off-by: Abdelatif Guettouche <abdelatif.guettouche@espressif.com>

sched/sched/sched_addreadytorun.c

@@ -143,7 +143,7 @@ bool nxsched_add_readytorun(FAR struct tcb_s *btcb)
  * - The caller has already removed the input rtcb from whatever list it
  *   was in.
  * - The caller handles the condition that occurs if the head of the
- *   ready-to-run list is changed.
+ *   ready-to-run list has changed.
  *
  ****************************************************************************/
 
@@ -162,7 +162,7 @@ bool nxsched_add_readytorun(FAR struct tcb_s *btcb)
 
   if ((btcb->flags & TCB_FLAG_CPU_LOCKED) != 0)
     {
-      /* Yes.. that that is the CPU we must use */
+      /* Yes.. that is the CPU we must use */
 
       cpu  = btcb->cpu;
     }

sched/sched/sched_cpuselect.c

@@ -67,23 +67,19 @@ int nxsched_select_cpu(cpu_set_t affinity)
   int cpu;
   int i;
 
-  /* Otherwise, find the CPU that is executing the lowest priority task
-   * (possibly its IDLE task).
-   */
-
   minprio = SCHED_PRIORITY_MAX;
   cpu     = IMPOSSIBLE_CPU;
 
   for (i = 0; i < CONFIG_SMP_NCPUS; i++)
     {
-      /* If the thread permitted to run on this CPU? */
+      /* Is the thread permitted to run on this CPU? */
 
       if ((affinity & (1 << i)) != 0)
         {
           FAR struct tcb_s *rtcb = (FAR struct tcb_s *)
                                    g_assignedtasks[i].head;
 
-          /* If this thread is executing its IDLE task, the use it.  The
+          /* If this CPU is executing its IDLE task, then use it.  The
            * IDLE task is always the last task in the assigned task list.
            */
 

sched/sched/sched_lock.c

@@ -85,10 +85,10 @@
  *    This assures that the scheduler does enforce the critical section.
  *    NOTE: Because of this spinlock, there should never be more than one
  *    bit set in 'g_cpu_lockset'; attempts to set additional bits should
- *    be cause the CPU to block on the spinlock.  However, additional bits
+ *    cause the CPU to block on the spinlock.  However, additional bits
  *    could get set in 'g_cpu_lockset' due to the context switches on the
  *    various CPUs.
- * 5. Each the time the head of a g_assignedtasks[] list changes and the
+ * 5. Each time the head of a g_assignedtasks[] list changes and the
  *    scheduler modifies 'g_cpu_lockset', it must also set 'g_cpu_schedlock'
  *    depending on the new state of 'g_cpu_lockset'.
  * 5. Logic that currently uses the currently running tasks lockcount

sched/sched/sched_mergeprioritized.c

@@ -39,7 +39,7 @@
  * Name: nxsched_merge_prioritized
  *
  * Description:
- *  This function merges the content of the prioritized task list '1ist1'
+ *  This function merges the content of the prioritized task list 'list1'
  *  into the prioritized task list, 'list2'.  On return 'list2' will contain
  *  the prioritized content of both lists; 'list1' will be empty.
  *

sched/sched/sched_unlock.c

@@ -263,7 +263,7 @@ int sched_unlock(void)
            * NOTE: This operation has a very high likelihood of causing
            * this task to be switched out!
            *
-           * In the single CPU case, decrementing irqcount to zero is
+           * In the single CPU case, decrementing lockcount to zero is
            * sufficient to release the pending tasks.  Further, in that
            * configuration, critical sections and pre-emption can operate
            * fully independently.
@@ -277,7 +277,7 @@ int sched_unlock(void)
 #if CONFIG_RR_INTERVAL > 0
           /* If (1) the task that was running supported round-robin
            * scheduling and (2) if its time slice has already expired, but
-           * (3) it could not slice out because pre-emption was disabled,
+           * (3) it could not be sliced out because pre-emption was disabled,
            * then we need to swap the task out now and reassess the interval
            * timer for the next time slice.
            */
@@ -285,7 +285,7 @@ int sched_unlock(void)
           if ((rtcb->flags & TCB_FLAG_POLICY_MASK) == TCB_FLAG_SCHED_RR &&
               rtcb->timeslice == 0)
             {
-              /* Yes.. that is the situation.  But one more thing.  The call
+              /* Yes.. that is the situation.  But one more thing:  The call
                * to up_release_pending() above may have actually replaced
                * the task at the head of the ready-to-run list.  In that
                * case, we need only to reset the timeslice value back to the