Fix typos

ReleaseNotes

@@ -3962,7 +3962,7 @@ Bugfixes (see the ChangeLog for details).  Some of these are very important:
 
     * Tasking:
 
-      - The wrong PID was being signalled with SIGCHILD.  It should be
+      - The wrong PID was being signalled with SIGCHLD.  It should be
         the PID of the task that create the task group, not the ID of
         the last thread to leave the task group.
       - Added logic so that some internal resources and states are recovered

include/signal.h

@@ -213,7 +213,7 @@
 
 /* struct sigaction flag values */
 
-#define SA_NOCLDSTOP    (1 << 0) /* Do not generate SIGCHILD when
+#define SA_NOCLDSTOP    (1 << 0) /* Do not generate SIGCHLD when
                                   * children stop (ignored) */
 #define SA_SIGINFO      (1 << 1) /* Invoke the signal-catching function
                                   * with 3 args instead of 1

sched/group/group_create.c

@@ -368,7 +368,7 @@ int group_initialize(FAR struct task_tcb_s *tcb)
 #endif
 
   /* Save the ID of the main task within the group of threads.  This needed
-   * for things like SIGCHILD.  It ID is also saved in the TCB of the main
+   * for things like SIGCHLD.  It ID is also saved in the TCB of the main
    * task but is also retained in the group which may persist after the main
    * task has exited.
    */

sched/sched/sched_waitid.c

@@ -123,7 +123,7 @@ int nx_waitid(int idtype, id_t id, FAR siginfo_t *info, int options)
     }
 
   /* None of the options are supported except for WEXITED (which must be
-   * provided.  Currently SIGCHILD always reports CLD_EXITED so we cannot
+   * provided.  Currently SIGCHLD always reports CLD_EXITED so we cannot
    * distinguish any other events.
    */
 

sched/task/task_exithook.c

@@ -264,7 +264,7 @@ static inline void nxtask_groupexit(FAR struct task_group_s *group)
  * Name: nxtask_sigchild
  *
  * Description:
- *   Send the SIGCHILD signal to the parent thread
+ *   Send the SIGCHLD signal to the parent thread
  *
  ****************************************************************************/
 
@@ -405,7 +405,7 @@ static inline void nxtask_sigchild(FAR struct tcb_s *ptcb,
  * Name: nxtask_signalparent
  *
  * Description:
- *   Send the SIGCHILD signal to the parent task group
+ *   Send the SIGCHLD signal to the parent task group
  *
  ****************************************************************************/
 
@@ -639,7 +639,7 @@ void nxtask_exithook(FAR struct tcb_s *tcb, int status, bool nonblocking)
 
   nxtask_recover(tcb);
 
-  /* Send the SIGCHILD signal to the parent task group */
+  /* Send the SIGCHLD signal to the parent task group */
 
   nxtask_signalparent(tcb, status);