lkdtm: Convert from jprobe to kprobe

The jprobe subsystem is being removed, so convert to using kprobe instead.

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>