This branch simplifies and clarifies the dcache lookup, and allows us to
do certain nice optimizations when comparing dentries.  It also cleans
up the interface to __d_lookup_rcu(), especially around passing the
inode information around.

* dentry-cleanups:
  vfs: make it possible to access the dentry hash/len as one 64-bit entry
  vfs: move dentry name length comparison from dentry_cmp() into callers
  vfs: do the careful dentry name access for all dentry_cmp cases
  vfs: remove unnecessary d_unhashed() check from __d_lookup_rcu
  vfs: clean up __d_lookup_rcu() and dentry_cmp() interfaces