Ideally, header files under include/linux shouldn't be adding
includes of other headers, in anticipation of their consumers,
but just the headers needed for the header itself to pass
parsing with CPP.

The module.h is particularly bad in this sense, as it itself does
include a whole bunch of other headers, due to the complexity of
module support.

There doesn't appear to be anything in net/ife.h that is module
related, and build coverage doesn't appear to show any other
files/drivers relying implicitly on getting it from here.

So it appears we are simply free to just remove it in this case.

Cc: Yotam Gigi <yotam.gi@gmail.com>
Cc: Jamal Hadi Salim <jhs@mojatatu.com>
Cc: "David S. Miller" <davem@davemloft.net>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>