lttng-tools: Fix path for test_python_looging

" was missing

Signed-off-by: Anders Wallin <anders.wallin@windriver.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
(cherry picked from commit e1780ccf)
Signed-off-by: Anuj Mittal <anuj.mittal@intel.com>