upload-pack: replace use of several hard-coded constants
Update several uses of hard-coded 40-based constants to use either
the_hash_algo or GIT_MAX_HEXSZ, as appropriate. Replace a combined use
of oid_to_hex and memcpy with oid_to_hex_r, which not only avoids the
need for a constant, but is more efficient. Make use of parse_oid_hex
to eliminate the need for constants and simplify the code at the same
time. Update some comments to no longer refer to SHA-1 as well.
Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>