The current code for reflog entries uses a lot of hard-coded constants,
making it hard to read and modify. Use parse_oid_hex and two temporary
variables to simplify the code and reduce the use of magic constants.
Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>