* Modified hwmp_recv_preq:
o cleaned up code, removed rootmac variable because preq->origaddr
is the root when we recevie a Proactive PREQ;
o Modified so that a PREP in response of a Proactive PREQ is unicast,
a PREP is ALWAYS unicast;
* Modified hwmp_recv_prep:
o Before we mark a route to be valid we should remove the discovery
flag and then mark it valid in such a way we wont lose the isgate flag;
Approved by: adrian