[NET]: Make netdev_chain a raw notifier.

From: Alan Stern <stern@rowland.harvard.edu>

This chain does it's own locking via the RTNL semaphore, and
can also run recursively so adding a new mutex here was causing
deadlocks.

Signed-off-by: David S. Miller <davem@davemloft.net>

diff --cc net/core/dev.c
Simple merge