Jeff King authored Feb 22, 2016 and Junio C Hamano committed Feb 22, 2016

This function allocate a packed_git flex-array, and adds a
mysterious 2 bytes to the length of the pack_name field. One
is for the trailing NUL, but the other has no purpose. This
is probably cargo-culted from add_packed_git, which gets the
".idx" path and needed to allocate enough space to hold the
matching ".pack" (though since 48bcc1c3

, we calculate the
size there differently).

This site, however, is using the raw path of a tempfile, and
does not need the extra byte. We can just replace the
allocation with FLEX_ALLOC_STR, which handles the allocation
and the NUL for us.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>