ggml : release the requested thread pool resource (#3292)

* Release the requested thread pool resource

* Release the requested thread pool resource 2

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Co-authored-by: Zongfu ZF3 Qu <quzf3@Lenovo.com>

ggml.c

@@ -89,7 +89,9 @@ static int pthread_create(pthread_t * out, void * unused, thread_ret_t(*func)(vo
 
 static int pthread_join(pthread_t thread, void * unused) {
     (void) unused;
-    return (int) WaitForSingleObject(thread, INFINITE);
+    int ret = (int) WaitForSingleObject(thread, INFINITE);
+    CloseHandle(thread);
+    return ret;
 }
 
 static int sched_yield (void) {