qemu/msi: clean used vectors state on load

Clean up msix vector usage state on load. Since guest might have control
over it through the device, the device will have to load this state from
file.
Signed-off-by: NMichael S. Tsirkin <mst@redhat.com>
Signed-off-by: NAnthony Liguori <aliguori@us.ibm.com>

hw/msix.c

@@ -302,6 +302,7 @@ void msix_load(PCIDevice *dev, QEMUFile *f)
         return;
     }
 
+    msix_free_irq_entries(dev);
     qemu_get_buffer(f, dev->msix_table_page, n * MSIX_ENTRY_SIZE);
     qemu_get_buffer(f, dev->msix_table_page + MSIX_PAGE_PENDING, (n + 7) / 8);
 }