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.homeSigned-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>

tools/testing/selftests/ftrace/test.d/kprobe/kprobe_syntax_errors.tc

@@ -21,7 +21,6 @@ check_error 'p:^/bar vfs_read'		# NO_GROUP_NAME
 check_error 'p:^12345678901234567890123456789012345678901234567890123456789012345/bar vfs_read'	# GROUP_TOO_LONG
 
 check_error 'p:^foo.1/bar vfs_read'	# BAD_GROUP_NAME
-check_error 'p:foo/^ vfs_read'		# NO_EVENT_NAME
 check_error 'p:foo/^12345678901234567890123456789012345678901234567890123456789012345 vfs_read'	# EVENT_TOO_LONG
 check_error 'p:foo/^bar.1 vfs_read'	# BAD_EVENT_NAME