rib: Add periodic invalid face clean up

refs: #1744, #1875

Change-Id: I4e6780ef6abb95b2c4ad7c1e6291897693cb551a
diff --git a/rib/rib.cpp b/rib/rib.cpp
index c76940b..0d33f24 100644
--- a/rib/rib.cpp
+++ b/rib/rib.cpp
@@ -279,6 +279,7 @@
               FaceEntry copy = *faceIt;
 
               faceIt = entry->eraseFace(faceIt);
+              m_nItems--;
 
               const bool captureWasTurnedOff = (hadCapture && !entry->hasCapture());
               createFibUpdatesForErasedFaceEntry(*entry, copy, captureWasTurnedOff);