ipv6: ip6_make_skb() needs to clear cork.base.dst

In my last patch, I missed fact that cork.base.dst was not initialized
in ip6_make_skb() :

If ip6_setup_cork() returns an error, we might attempt a dst_release()
on some random pointer.

Change-Id: I38676681fe8594bad3ef9270bb445e10c14778ac
Fixes: 862c03ee1deb ("ipv6: fix possible mem leaks in ipv6_make_skb()")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: syzbot <syzkaller@googlegroups.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Git-commit: 95ef498d977bf44ac094778fd448b98af158a3e6
Git-repo: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git


Signed-off-by: Tejaswi Tanikella <tejaswit@codeaurora.org>