Closing and establishing connection with serial console before login

libvirt/tests/src/virsh_cmd/domain/virsh_domif_setlink_getlink.py

@@ -254,6 +254,9 @@ def check_update_device(vm, if_name, session):
 
         error_msg = None
         if status_error == "no" and not post_action:
+            # Close then establish a connection with the serial console
+            vm.cleanup_serial_console()
+            vm.create_serial_console()
             # Serial login the vm to check link status
             # Start vm check the link statue
             session = vm.wait_for_serial_login(username=username,