Merge branch 'tun_rfs'

Zhi Yong Wu says:

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tun: add the RFS support

Since Tom Herbert's hash related patchset was modified and got merged,
his pachset about adding support for RFS on tun flows also need to get
adjusted accordingly. I tried to update them, and before i will start
to do some perf tests, i hope to get one correct code base, so it's time
to post them out now. Any constructive comments are welcome, thanks.
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Signed-off-by: David S. Miller <davem@davemloft.net>