packfile: drop sha1_pack_name()

The sha1_pack_name() function has a few ugly bits:

  - it writes into a static strbuf (and not even a ring buffer of them),
    which can lead to subtle invalidation problems

  - it uses the term "sha1", but it's really using the_hash_algo, which
    could be sha256

There's only one caller of it left. And in fact that caller is better
off using the underlying odb_pack_name() function itself, since it's
just copying the result into its own strbuf anyway.

Converting that caller lets us get rid of this now-obselete function.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Taylor Blau <me@ttaylorr.com>

packfile.c

@@ -35,12 +35,6 @@ char *odb_pack_name(struct strbuf *buf,
 	return buf->buf;
 }
 
-char *sha1_pack_name(const unsigned char *sha1)
-{
-	static struct strbuf buf = STRBUF_INIT;
-	return odb_pack_name(&buf, sha1, "pack");
-}
-
 char *sha1_pack_index_name(const unsigned char *sha1)
 {
 	static struct strbuf buf = STRBUF_INIT;