wt-status: pass struct repository through function parameters

wt-status: pass struct repository through function parameters

Some functions in wt-status.c (count_stash_entries(),
read_line_from_git_path(), abbrev_oid_in_line(), and
read_rebase_todolist()) rely on the_repository as they do not have access
to a local repository instance.

Add a struct repository *r parameter to these functions and pass the local
repository instance through the callers, which already have access to it
either directly by struct repository *r or indirectly by struct wt_state
*s (s->repo).

Replace uses of the_repository in these functions with the passed parameter.

Signed-off-by: Shreyansh Paliwal <shreyanshpaliwalcmsmn@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>