Fix compile check type failed in linux

Author: gangliao

paddle/gserver/tests/test_PyDataProvider2.cpp

@@ -321,7 +321,7 @@ TEST(PyDataProvider2, input_order) {
     if (!realBatchSize) {
       break;
     }
-    ASSERT_EQ(batch.getStreams().size(), 2);
+    ASSERT_EQ(batch.getStreams().size(), (size_t)2);
     for (size_t i = 0; i < realBatchSize; ++i) {
       ASSERT_EQ(batch.getStream(0).ids->getData()[i], 0);
       ASSERT_EQ(batch.getStream(1).ids->getData()[i], 1);

paddle/utils/tests/test_ThreadBarrier.cpp

@@ -32,7 +32,7 @@ void testNormalImpl(size_t thread_num,
 
  std::vector<std::thread> threads;
  threads.reserve(thread_num);
- for (int32_t i = 0; i < thread_num; ++i) {
+ for (size_t i = 0; i < thread_num; ++i) {
     threads.emplace_back([&thread_num, &mutex,
                          &tids, &barrier, &callback]{
         callback(thread_num, mutex, tids, barrier);