Remove the global tempHeader/stuff structures

Currently, volinodes.h defines an array ('stuff') for easily accessing
information about different inode types. Part of the array points to
parts of a global 'tempHeader' structure, making this not threadsafe.
Change this into an interface which utilizes local storage to make
this threadsafe and remove those horridly-named global variables.

This adds the init_inode_info static inline function, for initializing
a local inode information table.

Reviewed-on: http://gerrit.openafs.org/1869
Reviewed-by: Derrick Brashear <shadow@dementia.org>
Tested-by: Derrick Brashear <shadow@dementia.org>
(cherry picked from commit d8f2debce49a8a0eb310bdaf8ad0ee7601a0542e)

Change-Id: I1567e9184327b1cfa397b0bf37d611c2e8c2b8a1
Reviewed-on: http://gerrit.openafs.org/9409
Reviewed-by: Derrick Brashear <shadow@your-file-system.com>
Reviewed-by: Andrew Deason <adeason@sinenomine.net>
Reviewed-by: Stephan Wiesand <stephan.wiesand@desy.de>
Reviewed-by: Mark Vitale <mvitale@sinenomine.net>
Tested-by: BuildBot <buildbot@rampaginggeek.com>