Fix IndexError: Bad index 'None' type in fixture check_dut_asic_type (#…

…14075)

What is the motivation for this PR?
Due to #12824, rand_one_dut_hostname is None in fixture check_dut_asic_type
It throws failed on setup with "IndexError: Bad index 'None' type " in test case test_ecmp_hash_seed_value

How did you do it?
Use rand_one_dut_front_end_hostname in stead of rand_one_dut_hostname

How did you verify/test it?
Run PR test case and test_ecmp_hash_seed_value

tests/common/plugins/custom_fixtures/check_dut_asic_type.py

@@ -3,8 +3,8 @@
 
 
 @pytest.fixture(scope="function")
-def check_dut_asic_type(request, duthosts, rand_one_dut_hostname):
-    duthost = duthosts[rand_one_dut_hostname]
+def check_dut_asic_type(request, duthosts, rand_one_dut_front_end_hostname):
+    duthost = duthosts[rand_one_dut_front_end_hostname]
     asic_marks = [mark for mark in request.node.iter_markers(name="asic")]
     if not asic_marks:
         return