network_manager: Don't log errors for ignored interfaces

We currently print errors for interfaces we have ignored when neighbors
and addresses get added.

Change-Id: I58d643db8801837d603f807b1b12e80580ce390b
Signed-off-by: William A. Kennington III <wak@google.com>
diff --git a/src/network_manager.hpp b/src/network_manager.hpp
index 3f0eaab..74e4fb1 100644
--- a/src/network_manager.hpp
+++ b/src/network_manager.hpp
@@ -196,6 +196,7 @@
         std::unordered_map<InAddrAny, NeighborInfo> staticNeighs = {};
     };
     std::unordered_map<unsigned, UndiscoveredInfo> undiscoveredIntfInfo;
+    std::unordered_set<unsigned> ignoredIntf;
 
     /** @brief Map of enabled interfaces */
     std::unordered_map<unsigned, bool> systemdNetworkdEnabled;