- _SysFatalErrorHandler is supposed to be user-overridable.
The test case now installs its own handler to show that this
has happened properly.
- Use TC_PRINT() TC_ERROR() macros
- Since we have out own _SysFatalErrorHandler, show that
k_panic() works
- Show that _SysFatalErrorHandler gets invoked with the expected
reason code for some of the scenarios.
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>