hv_netvsc: use RCU to fix concurrent rx and queue changes

hv_netvsc: use RCU to fix concurrent rx and queue changes

[ Commit 02400fcee2542ee334a2394e0d9f6efd969fe782 upstream. ]

The receive processing may continue to happen while the
internal network device state is in RCU grace period.
The internal RNDIS structure is associated with the
internal netvsc_device structure; both have the same
RCU lifetime.

Defer freeing all associated parts until after grace
period.

Fixes: 0cf737808ae7 ("hv_netvsc: netvsc_teardown_gpadl() split")
Signed-off-by: Stephen Hemminger <sthemmin@microsoft.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>