builtin/blame.c: eliminate same_suspect()

builtin/blame.c: eliminate same_suspect()

Since the origin pointers are "interned" and reference-counted, comparing
the pointers rather than the content is enough.  The only uninterned
origins are cached values kept in commit->util, but same_suspect is not
called on them.

Signed-off-by: David Kastrup <dak@gnu.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>