qemu-iotests: _cleanup_qemu must be called on exit

qemu-iotests: _cleanup_qemu must be called on exit

For the tests that use the common.qemu functions for running a QEMU
process, _cleanup_qemu must be called in the exit function.

If it is not, if the qemu process aborts, then not all of the droppings
are cleaned up (e.g. pidfile, fifos).

This updates those tests that did not have a cleanup in qemu-iotests.

(I swapped spaces for tabs in test 102 as well)

Reported-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Jeff Cody <jcody@redhat.com>
Message-id: d59c2f6ad6c1da8b9b3c7f357c94a7122ccfc55a.1492544096.git.jcody@redhat.com