files_ref_store: put the packed files lock directly in this struct

Instead of using a global `lock_file` instance for the main
"packed-refs" file and using a pointer in `files_ref_store` to keep
track of whether it is locked, embed the `lock_file` instance directly
in the `files_ref_store` struct and use the new
`is_lock_file_locked()` function to keep track of whether it is
locked. This keeps related data together and makes the main reference
store less of a special case.

Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

0 files changed, 0 insertions, 0 deletions