ethernet_interface: Remove optional signal emission

We don't ever need to turn this off anymore, so we can simplify creation
arguments.

Change-Id: Idb1bde35041f16d409753ff661bfb248cfd4591e
Signed-off-by: William A. Kennington III <wak@google.com>
diff --git a/test/mock_ethernet_interface.hpp b/test/mock_ethernet_interface.hpp
index ff1b324..91e9bf5 100644
--- a/test/mock_ethernet_interface.hpp
+++ b/test/mock_ethernet_interface.hpp
@@ -12,8 +12,7 @@
   public:
     template <typename... Args>
     MockEthernetInterface(Args&&... args) :
-        EthernetInterface(std::forward<Args>(args)..., /*emitSignal=*/false,
-                          /*nicEnabled=*/true)
+        EthernetInterface(std::forward<Args>(args)..., /*nicEnabled=*/true)
     {
     }