virtio_net: verify if queue is broken after virtqueue_get_buf()
virtio_net: verify if queue is broken after virtqueue_get_buf()

If a virtqueue_get_buf() call returns a NULL pointer a possibly endless while
loop should be avoided by checking for a broken virtqueue.

Signed-off-by: Heinz Graalfs <46cdc05a0738b8bf21bd6f3a5ef6c9b9523cce3c@linux.vnet.ibm.com>
Signed-off-by: Rusty Russell <df9728c9e5104131c08c7adb03af425394842596@rustcorp.com.au>

KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs