[tests/crm] Fix python3 syntax error in test_acl_entry (sonic-net#9208)

What is the motivation for this PR?
Fix a python3 syntax error in testcase crm/test_crm.py::test_acl_entry. In python2 dict.keys() returns a list object, but in python3 it returns a dict_keys object which is not sortable.

How did you do it?
Use sorted() function instead of dict.keys().sort(). sorted() function can put the keys of a dict in a list in sorted order, and it has same action in Python2 and Python3.

How did you verify/test it?
Verified by running testcase on Marvell testbed.

Signed-off-by: Zhijian Li <zhijianli@microsoft.com>

Author: lizhijianrd

tests/crm/test_crm.py

@@ -910,8 +910,7 @@ def test_acl_entry(duthosts, enum_rand_one_per_hwsku_frontend_hostname, enum_fro
     if duthost.facts["asic_type"] == "marvell":
         # Remove DATA ACL Table and add it again with ports in same port group
         mg_facts = duthost.get_extended_minigraph_facts(tbinfo)
-        tmp_ports = mg_facts["minigraph_ports"].keys()
-        tmp_ports.sort(key=lambda x: int(x[8:]))
+        tmp_ports = sorted(mg_facts["minigraph_ports"], key=lambda x: int(x[8:]))
         for i in range(4):
             if i == 0:
                 ports = ",".join(tmp_ports[17:19])