migration: Move migration_total_bytes() to migration-stats.c

Once there rename it to migration_transferred_bytes() and pass a
QEMUFile instead of a migration object.

Signed-off-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Cédric Le Goater <clg@kaod.org>
Message-Id: <20230515195709.63843-7-quintela@redhat.com>
3 files changed