hw/net/net_tx_pkt: Decouple implementation from PCI

This is intended to be followed by another change for the interface.
It also fixes the leak of memory mapping when the specified memory is
partially mapped.

Fixes: e263cd49c7 ("Packet abstraction for VMWARE network devices")
Signed-off-by: Akihiko Odaki <akihiko.odaki@daynix.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
2 files changed