[IPV6] Remove three method declarations in include/net/ndisc.h.
[IPV6] Remove three method declarations in include/net/ndisc.h.

This patch removes two unused method declarations in
include/net/ndisc.h: ndisc_forwarding_on(void) and
ndisc_forwarding_off(void);

Also igmp6_cleanup(void) appears twice in this header, so one
igmp6_cleanup(void) declaration is removed.

Signed-off-by: Rami Rosen <d906574dd7f018d5d95e7b7a8107cdf708745f05@gmail.com>
Signed-off-by: David S. Miller <fe08d3c717adf2ae63592e4c9aec6e3e404d8e3e@davemloft.net>

KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas