pppd: Fix bounds check in EAP code am: f9fec5c369 am: 0adf11c24c am: 5788de2192 am: 024dbd1dc3 am: 39855b1e5b am: 80896b9c49 am: fdffd0deaf am: 7bbd97dd7c

Change-Id: I1fc6a925eb78a02501b0bf584453a9bc6d62e56c