linknx: fix build with gcc 6.x

Add a patch to fix the build of linknx with gcc 6.x.

Fixes:

  http://autobuild.buildroot.net/results/32e375e3f254ac19bed54a9e9fd6c1e9048e2043/

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
1 file changed