Finish dup logic for open files; fix bug in sigtimedwait(), would return wrong signo value if the signal was already pending

git-svn-id: svn://svn.code.sf.net/p/nuttx/code/trunk@5517 42af7a65-404d-4744-a932-0658087f49c3

sched/mq_initialize.c

@@ -217,11 +217,11 @@ void mq_initialize(void)
 
 void mq_desblockalloc(void)
 {
-  struct mq_des_block_s *mqdesblock;
+  FAR struct mq_des_block_s *mqdesblock;
 
   /* Allocate a block of message descriptors */
 
-  mqdesblock = (struct mq_des_block_s *)kmalloc(sizeof(struct mq_des_block_s));
+  mqdesblock = (FAR struct mq_des_block_s *)kmalloc(sizeof(struct mq_des_block_s));
   if (mqdesblock)
     {
       int i;

sched/sig_timedwait.c

@@ -228,7 +228,7 @@ int sigtimedwait(FAR const sigset_t *set, FAR struct siginfo *info,
 
       /* The return value is the number of the signal that awakened us */
 
-      ret = info->si_signo;
+      ret = sigpend->info.si_signo;
     }
 
   /* We will have to wait for a signal to be posted to this task. */

sched/task_vfork.c

@@ -291,7 +291,7 @@ pid_t task_vforkstart(FAR _TCB *child)
    * still running.
    */
 
-  while ((ret = kill(pid, 0)) == OK)
+  while (kill(pid, 0) == OK)
     {
       /* Yes.. then we can yield to it -- assuming that it has not lowered
        * its priority.  sleep(0) might be a safer thing to do since it does