Fix typo in sample build script to use LDFLAGS

Came in as github pull request #15

Signed-off-by: Gert Doering <gert@greenie.muc.de>
Acked-By: Arne Schwabe <arne@rfc2549.org>
(cherry picked from commit a95358af543b9106f4ef481e4556d1d03459d058)