t1000: modernize style

The preferred style in tests is:

    test_expect_success 'short description then sq to open the body' '
	    here comes the test &&
	    and chains over many lines &&
	    with closing sq on its own line
    '

Signed-off-by: Stefan Beller <[email protected]>
Signed-off-by: Junio C Hamano <[email protected]>

Author: stefanbeller