[fluid-lite] adjust to relative error (#22232)

- fluid和lite精度比较替换为相对误差

paddle/fluid/inference/tests/api/CMakeLists.txt

@@ -377,6 +377,7 @@ inference_analysis_test(lite_mul_model_test SRCS lite_mul_model_test.cc
 inference_analysis_test(lite_resnet50_test SRCS lite_resnet50_test.cc
         EXTRA_DEPS ${INFERENCE_EXTRA_DEPS}
         ARGS --infer_model=${RESNET50_MODEL_DIR})
+
 inference_analysis_test(test_analyzer_capi SRCS analyzer_capi_tester.cc
             EXTRA_DEPS ${INFERENCE_EXTRA_DEPS} paddle_fluid_c
             ARGS --infer_model=${RESNET50_MODEL_DIR}/model)

paddle/fluid/inference/tests/api/lite_resnet50_test.cc

@@ -63,7 +63,8 @@ TEST(AnalysisPredictor, use_gpu) {
   EXPECT_EQ(outputs.size(), expected_size);
   float* data_o = static_cast<float*>(outputs[0].data.data());
   for (size_t j = 0; j < outputs[0].data.length() / sizeof(float); j += 10) {
-    EXPECT_NEAR(data_o[j], truth_values[j / 10], 6e-3);
+    EXPECT_NEAR((data_o[j] - truth_values[j / 10]) / truth_values[j / 10], 0.,
+                10e-5);
   }
 }