fw: eliminate fibEntry in Strategy API

Strategy::lookupFib can be used to obtain FIB entry.
FIB lookup is skipped when strategy does not need it.

refs #3205

Change-Id: Icba67229cbc261d9def44ffa91461ea4b09982b2
diff --git a/daemon/fw/strategy.cpp b/daemon/fw/strategy.cpp
index e0dca89..2a40517 100644
--- a/daemon/fw/strategy.cpp
+++ b/daemon/fw/strategy.cpp
@@ -62,7 +62,7 @@
 
 void
 Strategy::afterReceiveNack(const Face& inFace, const lp::Nack& nack,
-                           shared_ptr<fib::Entry> fibEntry, shared_ptr<pit::Entry> pitEntry)
+                           shared_ptr<pit::Entry> pitEntry)
 {
   NFD_LOG_DEBUG("afterReceiveNack inFace=" << inFace.getId() <<
                 " pitEntry=" << pitEntry->getName());