selftests/kprobe: Do not test for GRP/ without event failures

selftests/kprobe: Do not test for GRP/ without event failures

A new feature is added where kprobes (and other probes) do not need to
explicitly state the event name when creating a probe. The event name will
come from what is being attached.

That is:

  # echo 'p:foo/ vfs_read' > kprobe_events

Will no longer error, but instead create an event:

  # cat kprobe_events
 p:foo/p_vfs_read_0 vfs_read

This should not be tested as an error case anymore. Remove it from the
selftest as now this feature "breaks" the selftest as it no longer fails
as expected.

Link: https://lore.kernel.org/all/1656296348-16111-1-git-send-email-quic_linyyuan@quicinc.com/
Link: https://lkml.kernel.org/r/20220712161707.6dc08a14@gandalf.local.home
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>