package/kodi-pvr-argustv: Fix compile error with gcc5

Fixes
http://autobuild.buildroot.net/results/dac/dacc3bd00ab2346d7655c0a1fb99f6c50b9da08b/
http://autobuild.buildroot.net/results/a6d/a6d3b510681f54f5625908930b4da73bf9edccf7/



Signed-off-by: Bernd Kuhls <bernd.kuhls@t-online.de>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>