style: made container APIs more consistent.

Change-Id: Ib4feedfc4c9fb497dfcd67e7e6a33ee03db58d7f
refs: #4337
diff --git a/src/route/fib.cpp b/src/route/fib.cpp
index 7e19100..752b15a 100644
--- a/src/route/fib.cpp
+++ b/src/route/fib.cpp
@@ -96,7 +96,7 @@
   std::map<ndn::Name, FibEntry>::iterator entryIt = m_table.find(name);
 
   // New FIB entry that has nextHops
-  if (entryIt == m_table.end() && hopsToAdd.getSize() != 0) {
+  if (entryIt == m_table.end() && hopsToAdd.size() != 0) {
     _LOG_DEBUG("New FIB Entry");
 
     FibEntry entry(name);
@@ -113,7 +113,7 @@
     _LOG_DEBUG("Existing FIB Entry");
 
     // Remove empty FIB entry
-    if (hopsToAdd.getSize() == 0) {
+    if (hopsToAdd.size() == 0) {
       remove(name);
       return;
     }