Revert "virtio_pci: fix out of bound access for msix_names"

This reverts commit de85ec8b.

Follow-up patches will revert 07ec5148 ("virtio_pci: use shared
interrupts for virtqueues") that triggered the problem so no need for
this one anymore.

Tested-by: Mike Galbraith <efault@gmx.de>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>