Fix: OOT lttng_logger tracepoint not visible with signed kernels

For the same reason as commit dd8d5afb3fabf853cb4c88c0a1a97f470090fe20,
the lttng_logger event was not working on signed kernels with non-signed
lttng modules.

Signed-off-by: Julien Desfossez <jdesfossez@efficios.com>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>