Remove self-set accuracy parameters of op tests: max_relative_error (#21823)

* Remove self-set accuracy parameters of op tests: max_relative_error
test=develop

* fix error
test=develop

python/paddle/fluid/tests/unittests/test_pad_op.py

@@ -43,7 +43,7 @@ class TestPadOp(OpTest):
         self.check_output()
 
     def test_check_grad_normal(self):
-        self.check_grad(['X'], 'Out', max_relative_error=0.006)
+        self.check_grad(['X'], 'Out')
 
     def initTestCase(self):
         self.shape = (16, 16)

python/paddle/fluid/tests/unittests/test_pool3d_op.py

@@ -261,10 +261,9 @@ class TestPool3d_Op(OpTest):
             return
         if self.has_cudnn() and self.pool_type != "max":
             place = core.CUDAPlace(0)
-            self.check_grad_with_place(
-                place, set(['X']), 'Out', max_relative_error=0.07)
+            self.check_grad_with_place(place, set(['X']), 'Out')
         elif self.pool_type != "max":
-            self.check_grad(set(['X']), 'Out', max_relative_error=0.07)
+            self.check_grad(set(['X']), 'Out')
 
     def init_data_format(self):
         self.data_format = "NCDHW"

python/paddle/fluid/tests/unittests/test_smooth_l1_loss_op.py

@@ -88,7 +88,7 @@ class TestSmoothL1LossOp2(OpTest):
         self.check_output()
 
     def test_check_grad_normal(self):
-        self.check_grad(['X', 'Y'], 'Out', max_relative_error=0.03)
+        self.check_grad(['X', 'Y'], 'Out')
 
     def test_check_grad_ingore_x(self):
         self.check_grad(