Use PROCESS/THREAD_QUERY_LIMITED_INFORMATION where appropriate

Using PROCESS/THREAD_QUERY_INFORMATION may limit the number of
processes/threads we can inspect depending on their integrity level.

Signed-off-by: Corinna Vinschen <corinna@vinschen.de>

winsup/cygwin/sched.cc

@@ -88,7 +88,8 @@ sched_getparam (pid_t pid, struct sched_param *param)
       set_errno (ESRCH);
       return -1;
     }
-  process = OpenProcess (PROCESS_QUERY_INFORMATION, FALSE, p->dwProcessId);
+  process = OpenProcess (PROCESS_QUERY_LIMITED_INFORMATION, FALSE,
+			 p->dwProcessId);
   if (!process)
     {
       set_errno (ESRCH);