control: Stop caching uninteresting service ifaces

In the code that adds the path/service/interface to the services cache,
there was one code path that would add every interface on the path to
the cache map instead of just the service being requested.  Change the
code to only add that single interface.

Signed-off-by: Matt Spinler <spinler@us.ibm.com>
Change-Id: I5c3d03d2855c4506dcf58fd1d805f1ec9ae3c25a
diff --git a/control/json/manager.cpp b/control/json/manager.cpp
index b5c517f..2351597 100644
--- a/control/json/manager.cpp
+++ b/control/json/manager.cpp
@@ -417,16 +417,12 @@
                 auto servIter = pathIter->second.find(itServ.first);
                 if (servIter != pathIter->second.end())
                 {
-                    // Service found in cache
-                    for (auto& itIntf : itServ.second)
+                    if (std::find(servIter->second.second.begin(),
+                                  servIter->second.second.end(),
+                                  intf) == servIter->second.second.end())
                     {
-                        if (std::find(servIter->second.second.begin(),
-                                      servIter->second.second.end(),
-                                      itIntf) == servIter->second.second.end())
-                        {
-                            // Add interface to cache
-                            servIter->second.second.emplace_back(itIntf);
-                        }
+                        // Add interface to cache
+                        servIter->second.second.emplace_back(intf);
                     }
                 }
                 else