As well as the basic conversion, I noticed that a lot of the
SCTP code checks gso_type without first checking skb_is_gso()
so I have added that where appropriate.
Also, document the helper.
Cc: Daniel Borkmann <daniel@iogearbox.net> Cc: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> Signed-off-by: Daniel Axtens <dja@axtens.net> Signed-off-by: David S. Miller <davem@davemloft.net>