qemu-img resize: Require --shrink for shrinking all image formats

qemu-img resize: Require --shrink for shrinking all image formats

QEMU 2.11 introduced the --shrink option for qemu-img resize to avoid
accidentally shrinking images (commit 4ffca8904a3). However, for
compatibility reasons, it was not enforced for raw images yet, but only
a deprecation warning was printed. This warning has existed for long
enough that we can now finally require --shrink for raw images, too, and
error out if it's not given.

Documentation already describes the state as it is after this patch.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20200710121717.28339-1-kwolf@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>