Use #pragma once as include guards

libtap/tap/basic.h

libtap/tap/float.h

libtap/tap/macros.h

src/common/base32hex.h

src/common/base64.h

src/common/crc.h

src/common/debug.h

src/common/descriptor.h

src/common/errcode.h

src/common/errors.h

src/common/evsched.h

src/common/fdset.h

src/common/getline.h

src/common/hattrie/hat-trie.h

src/common/hattrie/murmurhash3.h

src/common/heap.h

src/common/hex.h

src/common/hhash.h

src/common/lists.h

src/common/log.h