It holds an interned string, and git_attr_name() is a way to peek
into it. Make sure the involved pointer types are pointer-to-const.
Signed-off-by: Junio C Hamano <gitster@pobox.com> Signed-off-by: Stefan Beller <sbeller@google.com> Signed-off-by: Brandon Williams <bmwill@google.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>