Merge branch 'sctp-Some-sockopt-optlen-fixes'

Marcelo Ricardo Leitner says:

====================
sctp: Some sockopt optlen fixes

Hangbin Liu reported that some SCTP sockopt are allowing the user to get
the kernel to allocate really large buffers by not having a ceiling on
optlen.

This patchset address this issue (in patch 2), replace an GFP_ATOMIC
that isn't needed and avoid calculating the option size multiple times
in some setsockopt.
====================

Acked-by: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>