migration: Use savevm_handlers instead of loadvm copy

migration: Use savevm_handlers instead of loadvm copy

There is no reason for having the loadvm_handlers at all.  There is
only one use, and we can use the savevm handlers.

We will remove the loadvm handlers on a following patch.

Signed-off-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Laurent Vivier <lvivier@redhat.com>
Reviewed-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
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- Added load_version_id: version_id read from the stream (laurent)
- Added load_section_id: section_id read from the stream (dave)