libafs: remove linux conditionals for md5 inode number calculation

libafs: remove linux conditionals for md5 inode number calculation

Remove the conditionals which hide the md5 digest calculation for inode
numbers on non-linux platforms.  This feature was originally added to
support sites running on linux, but is generally useful and the
implementation is not specific to linux.

Reviewed-on: http://gerrit.openafs.org/11854
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Perry Ruiter <pruiter@sinenomine.net>
Reviewed-by: Benjamin Kaduk <kaduk@mit.edu>
(cherry picked from commit ac05e8ceebd05c2d8496759e70cf7b1b92541134)

Change-Id: I8fd613c436120a6436f48920ce4f33570dfb1fb8
Reviewed-on: https://gerrit.openafs.org/12632
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Benjamin Kaduk <kaduk@mit.edu>
Reviewed-by: Michael Meffie <mmeffie@sinenomine.net>
Reviewed-by: Mark Vitale <mvitale@sinenomine.net>
Reviewed-by: Stephan Wiesand <stephan.wiesand@desy.de>