sctp: use GFP_USER for user-controlled kmalloc

Commit cacc0621 ("sctp: use GFP_USER for user-controlled kmalloc")
missed two other spots.

For connectx, as it's more likely to be used by kernel users of the API,
it detects if GFP_USER should be used or not.

Fixes: cacc0621

 ("sctp: use GFP_USER for user-controlled kmalloc")
Reported-by: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>