gvfs-helper-client: properly update loose cache with fetched OID

Fix parsing of the "loose <odb>" response from `gvfs-helper` and
use the actually parsed OID when updating the loose oid cache.

Previously, an uninitialized "struct oid" was used to update
the cache.  This did not cause any corruption, but could cause
extra fetches for objects visited multiple times.

Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>

gvfs-helper-client.c

@@ -93,6 +93,9 @@ static void gh_client__update_loose_cache(const char *line)
 	if (!skip_prefix(line, "loose ", &v1_oid))
 		BUG("update_loose_cache: invalid line '%s'", line);
 
+	if (get_oid_hex(v1_oid, &oid))
+		BUG("update_loose_cache: invalid line '%s'", line);
+
 	odb_loose_cache_add_new_oid(gh_client__chosen_odb, &oid);
 }