[RFC net-next] treewide: s/is_<foo>_ether_addr/eth_addr_<foo>

Maybe all the is_<foo>_ether_addr  functions should be renamed
to eth_addr_<foo> for more api/style symmetry.

$ git grep --name-only -E "\bis_\w+_ether_addr" | \
  xargs sed -r -i -e 's/\bis_(\w+)_ether_addr\b/eth_addr_\1/g'
$ git diff --shortstat
 304 files changed, 690 insertions(+), 690 deletions(-)

Maybe add #defines of the old names for a few releases.