From: Xin Long <lucien.xin@gmail.com>
Date: Mon,  9 Dec 2019 13:45:18 +0800

Commit 312434617cb1 ("sctp: cache netns in sctp_ep_common") set netns
in asoc and ep base since they're created, and it will never change.
It's a better way to get netns from asoc and ep base, comparing to
calling sock_net().

This patch is to replace them.

v1->v2:
  - no change.

Suggested-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Acked-by: Neil Horman <nhorman@tuxdriver.com>

This looks like a cleanup rather than a bug fix, so net-next right?

Otherwise we need a Fixes: tag here and a better explanation in the
commit message about what problem this fixes.  Are the netns's wrong
sometimes without this conversion for example?

Thanks.