virtio_serial: clean temporary file after data transfer

Should clean temporary file even data transfer failed
Signed-off-by: NNana Liu <nanliu@redhat.com>

qemu/tests/virtio_serial_file_transfer.py

@@ -171,6 +171,7 @@ def transfer_data(params, vm, host_file_name=None, guest_file_name=None,
     """
     session = vm.wait_for_login()
     os_type = params["os_type"]
+    try:
         guest_path = params.get("guest_script_folder", "C:\\")
         guest_scripts = params.get("guest_scripts",
                                    "VirtIoChannel_guest_send_receive.py")
@@ -181,7 +182,7 @@ def transfer_data(params, vm, host_file_name=None, guest_file_name=None,
         transfer_timeout = int(params.get("transfer_timeout", 720))
         host_dir = data_dir.get_tmp_dir()
         guest_dir = params.get("tmp_dir", '/var/tmp/')
-    host_file_size, guest_file_size, host_action, guest_action\
+        host_file_size, guest_file_size, host_action, guest_action \
             = get_command_options(sender, file_size)
         if not host_file_name:
             host_file_name = generate_data_file(host_dir, host_file_size)
@@ -202,6 +203,7 @@ def transfer_data(params, vm, host_file_name=None, guest_file_name=None,
                       port_name, guest_file_name, guest_action))
         result = _transfer_data(
             session, host_cmd, guest_cmd, transfer_timeout, sender)
+    finally:
         if os_type == "windows":
             guest_file_name = guest_file_name.replace("/", "\\")
         if clean_file: