This fixes routing loops in PREP propagation and is in accordance with Draft
11, Section: 11C.9.8.4.
Signed-off-by: Fabrice Deyber <fabricedeyber@agilemesh.com>
Signed-off-by: Javier Cardona <javier@cozybit.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>