libtraceevent: Have unit test fail when any tests fail If any of the tests of the unit test fails, make sure it returns non-zero to allow tools that use this know that a test failed. Link: https://lore.kernel.org/linux-trace-devel/[email protected]/ Link: https://lore.kernel.org/linux-trace-devel/[email protected] Reported-by: Paul Mars <[email protected]> Signed-off-by: Steven Rostedt (Google) <[email protected]>