ptunit: pacify static analyzers

Some of the ptunit_result fields appear to be used uninitialized for
passed and skipped tests.  They are not but this is hard to figure out.

Zero-initialize the entire ptunit_result structure.

Change-Id: I672a3c05d68c9ed2606af87ea47103e8794a0429
Signed-off-by: Markus Metzger <markus.t.metzger@intel.com>
ptunit: check file name before printing

When printing a file name for error reporting, make sure the file name
is not NULL.  Print "<unknown>" in this case.

Change-Id: I967d2e470e743f8a05ae4451b1903da26873fb3e
Signed-off-by: Markus Metzger <markus.t.metzger@intel.com>
ptunit-selftest: avoid stack address escapes

The tests pfun_init_fail and frun_fini_fail use a stack-allocated test
fixture, provoke a ptunit error, and check that the returned error pointer
matches the test fixture's address.  In case this test fails, the address
of the stack-allocated test fixture is returned in the error report.

It's only used for error reporting ... let's avoid it nevertheless.

Change-Id: I7b61fdaf964e81ba05c7c0d57b2e83bab3c0fa83
Signed-off-by: Markus Metzger <markus.t.metzger@intel.com>
libipt: fix missing doxygen escapes in intel-pt.h

Change-Id: If3925fdbac26f2edfa9505bf37829b5b7449510d
Signed-off-by: Markus Metzger <markus.t.metzger@intel.com>