simplify FAM test command (#16980)

- we don't need to export vars, setting them should be sufficient
- make can change directories for us, no need to cd

tests/foreman/sys/test_fam.py

@@ -190,7 +190,7 @@ def test_positive_run_modules_and_roles(module_target_sat, setup_fam, ansible_mo
 
     # Execute test_playbook
     result = module_target_sat.execute(
-        f'export NO_COLOR=True && export PYTEST_DISABLE_PLUGIN_AUTOLOAD=1 && cd {FAM_ROOT_DIR} && make livetest_{ansible_module} PYTHON_COMMAND="python3" PYTEST_COMMAND="pytest-3.11"'
+        f'NO_COLOR=1 PYTEST_DISABLE_PLUGIN_AUTOLOAD=1 make --directory {FAM_ROOT_DIR} livetest_{ansible_module} PYTHON_COMMAND="python3" PYTEST_COMMAND="pytest-3.11"'
     )
     assert 'PASSED' in result.stdout
     assert result.status == 0