Linux: Load exportfs first

Linux: Load exportfs first

The changes to use the exportfs interface to access cache files
require that the exportfs module is loaded before our module.

In 'normal' operation depmod, and modprobe, would take care of
this for us, however our legacy installation format where we
ship the kernel module outside of /lib/modules stops modprobe from
working, and our init script uses insmod. So, explicitly load
exportfs first.

Note: I'm aware of just how much this sucks, and the fact that we
really should just tidy up all of the packaging and init scripts
around our kernel module - but this close to 1.6 branch is probably
not the time for those kinds of changes.

Change-Id: Icdc11482f4eb05419a806a2cd55852eaa5999638
Reviewed-on: http://gerrit.openafs.org/2443
Reviewed-by: Derrick Brashear <shadow@dementia.org>
Tested-by: Derrick Brashear <shadow@dementia.org>