Merge branch 'eth_proto_is_802_3'

Alexander Duyck says:

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Add eth_proto_is_802_3 to provide improved means of checking Ethertype

This patch series implements and makes use of eth_proto_is_802_3().  The
idea behind the function is to provide an optimized means of testing to
determine if a given Ethertype value is a length or 802.3 protocol number.
The standard path for this was to use ntohs(proto) and then perform a
comparison.  This adds a slight cost as it usually requires either a 16b
rotate or byte swap which can cost 1 cycle or more depending on the
processor.

I had previously addressed this for eth_type_trans, however in doing so I had
overlooked checking with sparse and had introduced a couple sparse warnings.
The first patch in this series fixes those sparse warnings as well as does
some additional optimization for big endian systems.  In addition it pushes
the code out into a separate function which can then be used in the other
patches to reduce the instruction count/processing time in those functions
as well.
====================

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