net: move __skb_tx_hash to dev.c

__skb_tx_hash function has no relation to flow_dissect so just move it
to dev.c

Signed-off-by: Jiri Pirko <jiri@resnulli.us>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --cc include/linux/netdevice.h
Simple merge

diff --cc include/linux/skbuff.h
Simple merge

diff --cc net/core/dev.c
Simple merge

diff --cc net/core/flow_dissector.c
Simple merge