selftests/ftrace: Exclude "(fault)" in testing add/remove eprobe events

The original test for adding and removing eprobes used synthetic events
and retrieved the filename from the open system call at the end of the
system call. This would allow it to always be loaded into the page tables
when accessed.

Masami suggested that the test was too complex for just testing add and
remove, so it was changed to test just adding and removing an event probe
on top of the start of the open system call event. Now it is possible that
the filename will not be loaded into memory at the time the eprobe is
triggered, and will result in "(fault)" being displayed in the event. This
causes the test to fail.

Account for "(fault)" also being one of the values of the filename field
of the event probe.

Link: https://lkml.kernel.org/r/20210907230429.5783d519@rorschach.local.home

Fixes: 079db707

 ("selftests/ftrace: Add test case to test adding and removing of event probe")
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>