Merge branch 'hn/create-reflog-simplify'

A small simplification of API.

* hn/create-reflog-simplify:
  refs: drop force_create argument of create_reflog API

diff --cc builtin/checkout.c
Simple merge

diff --cc refs.c
Simple merge

diff --cc refs.h
Simple merge

diff --cc refs/files-backend.c
Simple merge

diff --cc refs/packed-backend.c
Simple merge

diff --cc refs/refs-internal.h
Simple merge

diff --cc t/helper/test-ref-store.c
Simple merge

diff --cc t/t1406-submodule-ref-store.sh
Simple merge