[MLU] fix mlu ctest final. (#44404)

python/paddle/fluid/tests/unittests/mlu/test_c_comm_init_op_mlu.sh

@@ -17,5 +17,4 @@
 set -e
 # use default values
 # FIXME: random fails on Unknown command lines -c (or -m).
-launch_py=${PADDLE_BINARY_DIR}/python/paddle/distributed/launch.py
-MLU_VISIBLE_DEVICES=0,1 python ${launch_py} c_comm_init_op_mlu.py
+MLU_VISIBLE_DEVICES=0,1 python -m paddle.distributed.launch c_comm_init_op_mlu.py

python/paddle/fluid/tests/unittests/mlu/test_hard_swish_op_mlu.py

@@ -16,13 +16,13 @@ from __future__ import print_function
 import paddle.nn.functional as F
 import paddle.fluid as fluid
 import paddle
+import sys
+
+sys.path.append("..")
 from op_test import OpTest
 
 import numpy as np
 import unittest
-import sys
-
-sys.path.append("..")
 
 paddle.enable_static()
 SEED = 2021

python/paddle/fluid/tests/unittests/mlu/test_spawn_mlu.py

@@ -102,12 +102,13 @@ class TestSpawn(unittest.TestCase):
         self.assertEqual(nprocs, core.get_mlu_device_count())
 
     def test_spawn(self):
-        context = dist.spawn(train, backend='cncl', nprocs=4)
+        num_devs = core.get_mlu_device_count()
+        context = dist.spawn(train, backend='cncl', nprocs=num_devs)
         rank_list = []
-        for i in range(4):
+        for i in range(num_devs):
             rank_list.append(context.return_queues[i].get())
         rank_list.sort()
-        self.assertEqual(rank_list, list(range(4)))
+        self.assertEqual(rank_list, list(range(num_devs)))
 
 
 if __name__ == '__main__':