From: NeilBrown <neilb@cse.unsw.edu.au>

From: "William A.(Andy) Adamson" <andros@citi.umich.edu>

Compare inode pointers instead of dentry pointers when checking an inode
refered to by a stateid against an inode refered to by a file handle.

Set st_vfs_set to 0 if the stateid/file handle check fails to avoid
referencing bad state when reaping stateid's.