network_manager: Allow direct access to interfaces

Change-Id: I3dc2bb944b8d3a7873e26ce2958a2cb1d9be95af
Signed-off-by: William A. Kennington III <wak@google.com>
diff --git a/src/util.cpp b/src/util.cpp
index b1f4d39..9d58bcb 100644
--- a/src/util.cpp
+++ b/src/util.cpp
@@ -200,9 +200,9 @@
         [=]<int f>() noexcept { return isValidPrefix<f>(prefix); }, family);
 }
 
-InterfaceList getInterfaces()
+string_uset getSystemInterfaces()
 {
-    InterfaceList interfaces{};
+    string_uset interfaces;
     struct ifaddrs* ifaddr = nullptr;
 
     // attempt to fill struct with ifaddrs