LIB32: Avoid linking in unneeded (and invalid lib32) libz for libmagic build tool.
Usually this is just ignored:
/usr/bin/ld: skipping incompatible /scratch/obj/root/git/freebsd/amd64.amd64/obj-lib32/lib/libz/libz.so when searching for -lz /usr/bin/ld: skipping incompatible /scratch/obj/root/git/freebsd/amd64.amd64/obj-lib32/lib/libz/libz.a when searching for -lz
However some combination of newer toolchains simply fail here instead:
/usr/bin/ld: error: /home/dstolfa/obj/home/dstolfa/cadets/amd64.amd64/obj-lib32/lib/libz/libz.so is incompatible with /usr/lib/crt1.o
Libz is not needed for mkmagic so just exclude it.
Reported by: Domagoj Stolfa <domagoj.stolfa@gmail.com>
MFC after: 2 weeks
Sponsored by: Dell EMC