When "git submodule status" command tries to show the name of the
submodule HEAD revision more descriptively, but the submodule
repository lacked a suitable tag to do so, it leaked "fatal: cannot
describe" message to the UI. Squelch it by using '--always'.
Signed-off-by: Ping Yin <pkufranky@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>