network_manager: Cleanup map type

We want the map type to be a unique_map that allows and type of strings
for comparsion.

Change-Id: I22158e85d90256fe827a0a2fb389acb68bc909a1
Signed-off-by: William A. Kennington III <wak@google.com>
diff --git a/src/network_manager.cpp b/src/network_manager.cpp
index b3b28b4..bba2ca2 100644
--- a/src/network_manager.cpp
+++ b/src/network_manager.cpp
@@ -131,7 +131,7 @@
                 log<level::ERR>(msg.c_str());
                 continue;
             }
-            auto it = interfaces.find(std::string(interfaceName));
+            auto it = interfaces.find(interfaceName);
             if (it == interfaces.end())
             {
                 auto msg = fmt::format("Missing interface({}) for VLAN({}): {}",
@@ -146,7 +146,7 @@
         objPath /= interface;
         config::Parser config(config::pathForIntfConf(confDir, interface));
 
-        auto intf = std::make_shared<phosphor::network::EthernetInterface>(
+        auto intf = std::make_unique<phosphor::network::EthernetInterface>(
             bus, objPath.string(), config, *this);
 
         intf->createIPAddressObjects();