test: rtnetlink: use manager interface query

Use the new interface query method provided by manager to know if the
interface was added instead of inspecting the manager itself.

Change-Id: I94600199fd60a014d6b376155555449f7af617f5
Signed-off-by: Patrick Venture <venture@google.com>
diff --git a/test/mock_network_manager.hpp b/test/mock_network_manager.hpp
index 141469b..df3efdf 100644
--- a/test/mock_network_manager.hpp
+++ b/test/mock_network_manager.hpp
@@ -19,8 +19,6 @@
     }
 
     MOCK_METHOD1(restartSystemdUnit, void(const std::string& service));
-
-    friend class TestRtNetlink;
 };
 
 } // namespace network
diff --git a/test/test_rtnetlink.cpp b/test/test_rtnetlink.cpp
index 9284600..ecfa44a 100644
--- a/test/test_rtnetlink.cpp
+++ b/test/test_rtnetlink.cpp
@@ -77,13 +77,6 @@
         manager->setConfDir(confDir);
     }
 
-    bool isInterfaceAdded(std::string intf)
-    {
-        return manager->interfaces.find(intf) != manager->interfaces.end()
-                   ? true
-                   : false;
-    }
-
     void createNetLinkSocket()
     {
         // RtnetLink socket
@@ -109,7 +102,7 @@
     nlMsg->nlmsg_seq = 0;
     nlMsg->nlmsg_pid = getpid();
 
-    EXPECT_EQ(false, isInterfaceAdded("igb5"));
+    EXPECT_EQ(false, manager->hasInterface("igb5"));
     // Send the request
     send(smartSock(), nlMsg, nlMsg->nlmsg_len, 0);
 
@@ -121,7 +114,7 @@
         sd_event_run(eventPtr.get(), 10);
     };
 
-    EXPECT_EQ(true, isInterfaceAdded("igb5"));
+    EXPECT_EQ(true, manager->hasInterface("igb5"));
 }
 
 } // namespace network