CheckForPthreads.c: Do not use C++-style comments in C source

Modules/CheckForPthreads.c

@@ -16,8 +16,8 @@ int main(int ac, char*av[]){
   pthread_create(&tid[0], 0, runner, (void*)1);
   pthread_create(&tid[1], 0, runner, (void*)2);
 
-#if defined(__BEOS__) && !defined(__ZETA__) // (no usleep on BeOS 5.)
-  usleep(1); // for strange behavior on single-processor sun
+#if defined(__BEOS__) && !defined(__ZETA__) /* (no usleep on BeOS 5.) */
+  usleep(1); /* for strange behavior on single-processor sun */
 #endif
 
   pthread_join(tid[0], 0);