UPSTREAM: net: Remove __sk_dst_reset() in tcp_v6_connect()

Remove __sk_dst_reset() in the failure handling because __sk_dst_reset()
will eventually get called when sk is released. No need to handle it in
the protocol specific connect call.
This is also to make the code path consistent with ipv4.

Bug: 63449462
Test: Tests in https://android-review.googlesource.com/535357/

 pass
Change-Id: I91d59909d1482b093904bd92703fc58af34d570f
Signed-off-by: Wei Wang <weiwan@google.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
(cherry-picked from commit 25776aa943401662617437841b3d3ea4693ee98a)