Staging: lustre: statahead: Remove ll_sa_entry_unhashed wrapper

Remove the function ll_sa_entry_unhashed() and replace all its calls
with the function list_empty() that it wrapped.

Signed-off-by: Shivani Bhardwaj <shivanib134@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>