qemu_loadvm_state is too long, and we can simplify it by splitting up
with three helper functions.

Signed-off-by: zhanghailiang <zhang.zhanghailiang@huawei.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Amit Shah <amit.shah@redhat.com>
Message-Id: <1452829066-9764-4-git-send-email-zhang.zhanghailiang@huawei.com>
Signed-off-by: Amit Shah <amit.shah@redhat.com>