Merge branch 'smc-next'

Ursula Braun says:

====================
smc fixes from 2018-04-17 - v3

in the mean time we challenged the benefit of these CLC handshake
optimizations for the sockopts TCP_NODELAY and TCP_CORK.
We decided to give up on them for now, since SMC still works
properly without.
There is now version 3 of the patch series with patches 2-4 implementing
sockopts that require special handling in SMC.

Version 3 changes
   * no deferring of setsockopts TCP_NODELAY and TCP_CORK anymore
   * allow fallback for some sockopts eliminating SMC usage
   * when setting TCP_NODELAY always enforce data transmission
     (not only together with corked data)

Version 2 changes of Patch 2/4 (and 3/4):
   * return error -EOPNOTSUPP for TCP_FASTOPEN sockopts
   * fix a kernel_setsockopt() usage bug by switching parameter
     variable from type "u8" to "int"
   * add return code validation when calling kernel_setsockopt()
   * propagate a setsockopt error on the internal CLC socket
     to the SMC socket.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>