ipv6: suppress sparse warnings in IP6_ECN_set_ce()

ipv6: suppress sparse warnings in IP6_ECN_set_ce()

[ Upstream commit c15c0ab12fd62f2b19181d05c62d24bc9fa55a42 ]

Pass the correct type __wsum to csum_sub() and csum_add(). This doesn't
really change anything since __wsum really *is* __be32, but removes the
address space warnings from sparse.

Cc: Eric Dumazet <edumazet@google.com>
Fixes: 34ae6a1aa054 ("ipv6: update skb->csum when CE mark is propagated")
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>