Linux: switch to evict_inode

Linux: switch to evict_inode

In 2.6.36, the delete_inode and clear_inode inode operations
are replaced by evict_inode.
Rename our current clear_inode to evict_inode, and add a few
things that were previously handled by the generic delete_inode.

This is required for 2.6.36.

Reviewed-on: http://gerrit.openafs.org/2544
Reviewed-by: Derrick Brashear <shadow@dementia.org>
Tested-by: Derrick Brashear <shadow@dementia.org>
(cherry-picked from commit fb01fbd7cd2d396df8a4605eaad9febc52ef3b61)

Reviewed-on: http://gerrit.openafs.org/2552
Reviewed-by: Derrick Brashear <shadow@dementia.org>
Tested-by: Derrick Brashear <shadow@dementia.org>
(cherry picked from commit e05b5937201ec313d2c8fa863f4dacec87ab687d)
Change-Id: I42a22dbea4f880f5c8bb1cd0904f1711b3a48292
Reviewed-on: http://gerrit.openafs.org/3517
Reviewed-by: Simon Wilkinson <sxw@inf.ed.ac.uk>