t5500: prettify non-commit tag tests

t5500: prettify non-commit tag tests

We don't need to use backslash continuation, as the "&&"
already provides continuation (and happily soaks up empty
lines between commands).

We can also expand the multi-line printf into a
here-document, which lets us use line breaks more naturally
(and avoids another continuation that required us to break
the natural indentation).

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>