openpic_kvm: drop address_space_to_flatview call

openpic_kvm: drop address_space_to_flatview call

The MemoryListener is registered on address_space_memory, there is
not much to assert.  This currently works because the callback
is invoked only once when the listener is registered, but section->fv
is the _new_ FlatView, not the old one on later calls and that
would break.

This confines address_space_to_flatview to exec.c and memory.c.

Acked-by: David Gibson <david@gibson.dropbear.id.au>
Reviewed-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>