Drop parsing pack filename SHA1 part, no one cares the filename

src/pack.c

@@ -997,11 +997,6 @@ int git_packfile_alloc(struct git_pack_file **pack_out, const char *path)
 		return -1;
 	}
 
-	/* see if we can parse the sha1 oid in the packfile name */
-	if (path_len < 40 ||
-		git_oid_fromstr(&p->sha1, path + path_len - GIT_OID_HEXSZ) < 0)
-		memset(&p->sha1, 0x0, GIT_OID_RAWSZ);
-
 	*pack_out = p;
 
 	return 0;

src/pack.h

@@ -88,7 +88,6 @@ struct git_pack_file {
 	int index_version;
 	git_time_t mtime;
 	unsigned pack_local:1, pack_keep:1, has_cache:1;
-	git_oid sha1;
 	git_oidmap *idx_cache;
 	git_oid **oids;