qemu-img: improve queue depth validation in img_bench This error was discovered by fuzzing qemu-img. Currently, running `qemu-img bench -d 0` in img_bench is allowed, which is a pointless operation and causes qemu-img to hang. Signed-off-by: Denis Rastyogin <gerben@altlinux.org> Message-ID: <20250327162423.25154-5-gerben@altlinux.org> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>