qemu: migration: Refresh device information after transferring state

qemu: migration: Refresh device information after transferring state

In my first approach in 4b480d10768c I overlooked the comment in
qemuMigrationRunIncoming stating that during actual migration the
qemuMigrationRunIncoming does not wait until the migration is complete
but rather offloads that to the Finish phase of migration.

This means that during actual migration qemuProcessRefreshState was
called prior to qemu actually transferring the full state and thus the
queries did not get the correct information. The approach worked only
for restore, where we wait for the migration to finish during qemu
startup.

Fix the issue by calling qemuProcessRefreshState both from
qemuProcessStart if there's no incomming migration and from
qemuMigrationFinish so that the code actually works as expected.