init: Avoid "No child processes" error spam

gui/loginui.cpp

@@ -46,7 +46,7 @@ Result<int> luna_main(int argc, char** argv)
         return 1;
     }
 
-    TRY(os::Security::pledge("stdio rpath wpath proc exec id", nullptr));
+    TRY(os::Security::pledge("stdio rpath wpath unix proc exec id", nullptr));
 
     setsid();
 

system/init.cpp

@@ -324,6 +324,7 @@ static void wait_for_child(int)
     auto rc = os::Process::wait(os::Process::ANY_CHILD, &status);
     if (rc.has_error())
     {
+        if (rc.error() == ECHILD) return;
         do_log("[init] waitpid error %s", rc.error_string());
         return;
     }