ipv6: protocol for address routes

This fixes a problem spotted with zebra, but not sure if it is
necessary a kernel problem.  With IPV6 when an address is added to an
interface, Zebra creates a duplicate RIB entry, one as a connected
route, and other as a kernel route.

When an address is added to an interface the RTN_NEWADDR message
causes Zebra to create a connected route. In IPV4 when an address is
added to an interface a RTN_NEWROUTE message is set to user space with
the protocol RTPROT_KERNEL. Zebra ignores these messages, because it
already has the connected route.

The problem is that route created in IPV6 has route protocol ==
RTPROT_BOOT.  Was this a design decision or a bug? This fixes it. Same
patch applies to both net-2.6 and stable.

Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: David S. Miller <davem@davemloft.net>