LU-4423 llite: get rid of lustre_dump_dentry()

LU-4423 llite: get rid of lustre_dump_dentry()

it's not only badly racy, it's actually dead code - the call in
ll_invalidate_aliases() is unreachable.  For an alias of our inode
to be root dentry, the inode would have to be its ->d_inode, aka
the root inode, and we never call ll_invalidate_aliases() for that.

Linux-commit: 5e9e2040247ac19a46d6627736ece726c46f1fdf

Change-Id: Ic5e475102793424396bb8b173eb8d9a3b020bd82
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: James Simmons <uja.ornl@yahoo.com>
Reviewed-on: https://review.whamcloud.com/25639
Tested-by: Jenkins
Tested-by: Maloo <hpdd-maloo@intel.com>
Reviewed-by: Patrick Farrell <paf@cray.com>
Reviewed-by: Jinshan Xiong <jinshan.xiong@intel.com>
Reviewed-by: Oleg Drokin <oleg.drokin@intel.com>