Since we don't care about how many bytes were written, simplify the return
value logic.
log_ref_write_fd() was written long before strbuf was fleshed out. Remove
the old manual buffer management code and replace it with strbuf(). Also
update copy_reflog_msg() which is called only by log_ref_write_fd() to use
strbuf as it keeps things consistent.
Signed-off-by: Ben Peart <Ben.Peart@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
80a6c2073b