The patch restores what commit 4a0962abd187df29b7d1378b2f372a55667d54c0
already implemented. The feature was subsequently clobbered by
commit da3bbdd4632c0171406b2677e31494afa5bde2f8
Before this patch some execution path use list_del() instead of
list_del_init() which results in inconsitencies in the state of d_lru
when the object is freed.
The performance of list_del_init() and list_del() is the same.
So lets just have one dentry removal function named dentry_lru_del() that always
does a list_del_init().
The result of this patch is that dentry->d_lru is now always empty when a
dentry is freed. The dentry defragmentation patch depends on a defined state
of a dentry on free.
Signed-off-by: Christoph Lameter <cl@xxxxxxxxxxxxxxxxxxxx>