pack-write: simplify index_pack_lockfile using skip_prefix() and xstrfmt()
pack-write: simplify index_pack_lockfile using skip_prefix() and xstrfmt()

Get rid of magic string length constants by using skip_prefix() instead
of memcmp() and use xstrfmt() for building a string instead of a
PATH_MAX-sized buffer, snprintf() and xstrdup().

Signed-off-by: Rene Scharfe <2da278a99b557fc93ddbed7517a413ad793e2e6a@web.de>
Signed-off-by: Junio C Hamano <a6723cc3f76163bf7adb636a73ac3b0ceb3e6b9b@pobox.com>

destenson/git,destenson/git,destenson/git,destenson/git,destenson/git,destenson/git,destenson/git,destenson/git