t: assume test_cmp produces verbose output

t: assume test_cmp produces verbose output

Some tests call test_cmp, and if it fails show the actual
output generated. This is mostly pointless, as test_cmp will
already show a diff between the expected and actual output.
It also fools --chain-lint by putting an "||" in the middle
of the chain, so we'd rather not use this construct.

Note that these cases actually show a pre-processed version
of the data, rather than exactly what test_cmp would show.
However, test_cmp's output is generally good for pointing
the user in the right direction, and they can then dig in
the trash directory themselves if they want to see more
details.

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