Remove the global tempHeader/stuff structures

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.

Change-Id: If4562e724fd7a8e5f8166ea0fe409d6765d0de2b
Reviewed-on: http://gerrit.openafs.org/1869
Reviewed-by: Derrick Brashear <shadow@dementia.org>
Tested-by: Derrick Brashear <shadow@dementia.org>