Build fails without -fpermissive

[a17r]

[ 35%] Building CXX object CMakeFiles/iccexamin.dir/icc_examin.cpp.o /usr/bin/x86_64-pc-linux-gnu-g++ -I/var/tmp/portage/media-gfx/icc_examin-0.56_p20171007/work/icc-examin-0.56_p20171007 -I/var/tmp/portage/media-gfx/icc_examin-0.56_p20171007/work/icc-examin-0.56_p20171007/FL -I/var/tmp/portage/media-gfx/icc_examin-0.56_p20171007/work/icc-examin-0.56_p20171007/Flmm -I/var/tmp/portage/media-gfx/icc_examin-0.56_p20171007/work/icc_examin-0.56_p20171007_build -I/usr/include/oyranos -I/usr/include/fltk -I/usr/include/freetype2 -DNDEBUG -O2 -march=amdfam10 -pipe -fomit-frame-pointer -floop-interchange -floop-strip-mine -floop-block -o CMakeFiles/iccexamin.dir/icc_examin.cpp.o -c /var/tmp/portage/media-gfx/icc_examin-0.56_p20171007/work/icc-examin-0.56_p20171007/icc_examin.cpp /var/tmp/portage/media-gfx/icc_examin-0.56_p20171007/work/icc-examin-0.56_p20171007/icc_examin.cpp: In constructor ‘ICCexamin::ICCexamin()’: /var/tmp/portage/media-gfx/icc_examin-0.56_p20171007/work/icc-examin-0.56_p20171007/icc_examin.cpp:220:36: error: invalid conversion from ‘int (*)(int, const void*, const char*, ...)’ to ‘oyMessage_f {aka int (*)(int, void*, const char*, ...)}’ [-fpermissive] oyMessageFuncSet( iccMessageFunc );

See also build.log: https://gist.github.com/a17r/36b97e8ee91280c597ffc3af29d04c09