Merge branch 'sk_txhash'

Tom Herbert says:

====================
net: Initialize sk_hash to random value and reset for failing cnxs

This patch set implements a common function to simply set sk_txhash to
a random number instead of going through the trouble to call flow
dissector. From dst_negative_advice we now reset the sk_txhash in hopes
of finding a better ECMP path through the network. Changing sk_txhash
affects:
  - IPv6 flow label and UDP source port which affect ECMP in the network
  - Local ECMP route selection (pending changes to use sk_txhash)
====================

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