virtio: device removal fixes

Here are a couple of fixes for virtio device removal.
Since these fix regressions (for devices with msi-x capability), I think we need them for 2.6.31.

Changes since v1:
- rewrote the patches according to Rusty's comments

Michael S. Tsirkin (2):
virtio: fix double free_irq on device removal
virtio: fix memory leak on device removal

 drivers/virtio/virtio_pci.c |   66 ++++++++++++++++++++++++------------------
 1 files changed, 38 insertions(+), 28 deletions(-)