Code cleanup in libknot

Knot.files

src/libknot/dname.c

src/libknot/hash/cuckoo-hash-table.c

src/libknot/nameserver/name-server.c

src/libknot/nameserver/name-server.h

src/libknot/packet/packet.c

src/libknot/packet/query.c

src/libknot/packet/query.h

src/libknot/packet/response.c

src/libknot/rdata.c

src/libknot/rrset.c

src/libknot/tsig-op.c

src/libknot/tsig.c

src/libknot/updates/changesets.c

src/libknot/updates/changesets.h

src/libknot/updates/xfr-in.c

src/libknot/updates/xfr-in.h

src/libknot/zone/node.c

src/libknot/zone/zone-contents.c

src/libknot/zone/zone-contents.h