staging: lustre: llite: remove obsolete comment for ll_unlink()

Remove obsolete comments about the behavior of ll_unlink()

Signed-off-by: John L. Hammond <john.hammond@intel.com>
Intel-bug-id: https://jira.hpdd.intel.com/browse/LU-8003
Reviewed-on: http://review.whamcloud.com/19881


Reviewed-by: Andrew Perepechko <andrew.perepechko@seagate.com>
Reviewed-by: James Simmons <uja.ornl@yahoo.com>
Reviewed-by: Oleg Drokin <oleg.drokin@intel.com>
Signed-off-by: James Simmons <jsimmons@infradead.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>