rpcrt4/tests: Use the available ARRAY_SIZE() macro.

dlls/rpcrt4/tests/cstub.c

@@ -596,7 +596,7 @@ static IPSFactoryBuffer *test_NdrDllGetClassObject(void)
 #undef VTBL_PROXY_TEST
 #undef VTBL_PROXY_TEST_NOT_ZERO
 
-    for (i = 0; i < sizeof(interfaces)/sizeof(interfaces[0]); i++)
+    for (i = 0; i < ARRAY_SIZE(interfaces); i++)
         ok( proxy_vtbl[i]->header.piid == interfaces[i],
             "wrong proxy %u iid %p/%p\n", i, proxy_vtbl[i]->header.piid, interfaces[i] );
 

dlls/rpcrt4/tests/rpc.c

@@ -149,10 +149,8 @@ static void TestDceErrorInqText (void)
                          */
     DWORD dwCount;
 
-    dwCount = FormatMessageA (FORMAT_MESSAGE_FROM_SYSTEM | 
-              FORMAT_MESSAGE_IGNORE_INSERTS,
-              NULL, RPC_S_NOT_RPC_ERROR, 0, bufferInvalid,
-              sizeof(bufferInvalid)/sizeof(bufferInvalid[0]), NULL);
+    dwCount = FormatMessageA(FORMAT_MESSAGE_FROM_SYSTEM | FORMAT_MESSAGE_IGNORE_INSERTS, NULL,
+            RPC_S_NOT_RPC_ERROR, 0, bufferInvalid, ARRAY_SIZE(bufferInvalid), NULL);
 
     /* A random sample of DceErrorInqText */
     /* 0 is success */

dlls/rpcrt4/tests/server.c

@@ -313,7 +313,7 @@ void __cdecl s_get_number_array(int x[20], int *n)
 {
   int c[] = {0, 1, 2, 3, 4, 5, 6, 7, 8, 9};
   memcpy(x, c, sizeof(c));
-  *n = sizeof(c)/sizeof(c[0]);
+  *n = ARRAY_SIZE(c);
 }
 
 int __cdecl s_sum_cs(cs_t *cs)