mgmt: ForwarderStatus equality operators and formatted output

Change-Id: I6d814ef427a9db38ef46427888f3b3ba982bf641
Refs: #3903
diff --git a/src/mgmt/nfd/channel-status.cpp b/src/mgmt/nfd/channel-status.cpp
index c2a9b63..f3a7e2b 100644
--- a/src/mgmt/nfd/channel-status.cpp
+++ b/src/mgmt/nfd/channel-status.cpp
@@ -106,9 +106,9 @@
 }
 
 std::ostream&
-operator<<(std::ostream& os, const ChannelStatus& cs)
+operator<<(std::ostream& os, const ChannelStatus& status)
 {
-  return os << "Channel(" << "LocalUri: " << cs.getLocalUri() << ")";
+  return os << "Channel(LocalUri: " << status.getLocalUri() << ")";
 }
 
 } // namespace nfd