qemu-iotests: Remove CR line endings in reference output

qemu doesn't print these CRs any more. The test still didn't fail
because the output comparison ignores line endings, but the change turns
up each time when you want to update the output.
Signed-off-by: NKevin Wolf <kwolf@redhat.com>
Reviewed-by: NMax Reitz <mreitz@redhat.com>