lttng-modules: fix shell syntax

* add missing space to fix:
  /bin/sh: 1: [: Illegal number: 119)
  shown in the log.do_compile (isn't fatal for the build)

Signed-off-by: Martin Jansa <Martin.Jansa@gmail.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
(cherry picked from commit 8f785f35)
Signed-off-by: Steve Sakoman <steve@sakoman.com>