tests: move --port-file and --trace-path-prefix arguments up one level

tests: move --port-file and --trace-path-prefix arguments up one level

Specify the --port-file and --trace-path-prefix arguments in function
get_cli_output_with_lttng_live_server rather than function
lttng_live_server.

Change-Id: Iddb781b8a085b85468f4148708409c774c79893f
Signed-off-by: Simon Marchi <simon.marchi@efficios.com>
Reviewed-on: https://review.lttng.org/c/babeltrace/+/10917
Tested-by: jenkins <jenkins@lttng.org>
Reviewed-by: Philippe Proulx <eeppeliteloop@gmail.com>