Use return codes from test programs to simplify test scripts
Forwarding the exit codes from the underlying test programs can simplify the test scripts that encapsulate the test programs.
For example, the switch_id test program checks the user id and returns early when we are not root. The test_switch_id.sh script does the same check which is redunant code if we change the return code in the test program and let the script forward it to the test driver.
Other test scripts can be simplified in a similar way.