ipv6: don't set DST_NOCOUNT for remotely added routes

[ Upstream commit c88507fbad8055297c1d1e21e599f46960cbee39 ]

DST_NOCOUNT should only be used if an authorized user adds routes
locally. In case of routes which are added on behalf of router
advertisments this flag must not get used as it allows an unlimited
number of routes getting added remotely.

Change-Id: I059d20cd2dcac154f1cc264241b4e77a98cc9484
Signed-off-by: Sabrina Dubroca <sd@queasysnail.net>
Acked-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>