Merge branch 'is_kdump_kernel'

Amir Vadai says:

====================
Make is_kdump_kernel() accessible from modules

I'm re-spinning this patchset. At the begining it was suggested to use a
different name for the parameter, but at the end [3] the resolution was to
leave it as it is in this patch.

Drivers need to know if running from kdump kernel in order to change their
memory profile - since kdump environment is limited by available memory.
Currently there are drivers that are using reset_devices as suggested in [2].
In [2] it was suggested to use reset_devices, but the context was, to enable
driver to know when the hardware device is needed to be reset, and not if this
is a kdump environment. We think that is_kdump_kernel() is better suited to
select between different memory profiles.

The first patch in this patchset exports a needed symbol in order to make
is_kdump_kernel() accessible from the drivers. The rest of the patches change
from reset_devices to is_kdump_kernel() in 2 networking drivers.

The idea of this patchset was suggested by Vivek Goyal.

Tested (only build) and applied on top of commit 8fc54f6: ("net: use
reciprocal_scale() helper")

[1] - ea1c1af: ("net/mlx4_en: Reduce memory consumption on kdump kernel")
[2] - https://lkml.org/lkml/2011/1/27/341
[3] - http://www.spinics.net/lists/netdev/msg291492.html
====================

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