packfile: replace sha1_to_hex

Replace a use of sha1_to_hex with hash_to_hex so that this code works
with a hash algorithm other than SHA-1.

Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

packfile.c

@@ -19,12 +19,12 @@
 #include "commit-graph.h"
 
 char *odb_pack_name(struct strbuf *buf,
-		    const unsigned char *sha1,
+		    const unsigned char *hash,
 		    const char *ext)
 {
 	strbuf_reset(buf);
 	strbuf_addf(buf, "%s/pack/pack-%s.%s", get_object_directory(),
-		    sha1_to_hex(sha1), ext);
+		    hash_to_hex(hash), ext);
 	return buf->buf;
 }