sched/sched: Validate priority before applying sporadic parameters.

nxsched_set_param() applied the sporadic parameters and restarted the
replenishment timer in set_sporadic_param() before nxsched_reprioritize()
rejected an out-of-range priority with EINVAL, leaving stale sporadic
state (e.g. a truncated hi_priority) behind on failure.

Validate sched_priority up front so the error path is atomic.

Assisted-by: OpenAI Codex
Signed-off-by: yushuailong <yyyusl@qq.com>

sched/sched/sched_setparam.c

@@ -187,6 +187,12 @@ int nxsched_set_param(pid_t pid, FAR const struct sched_param *param)
 
   if (param != NULL)
     {
+      if (param->sched_priority < SCHED_PRIORITY_MIN ||
+          param->sched_priority > SCHED_PRIORITY_MAX)
+        {
+          return -EINVAL;
+        }
+
       /* Prohibit modifications to the head of the ready-to-run task
        * list while adjusting the priority
        */