handler: fix undefined behavior

Saving a reference to a temporary returned from a function call is
undefined behavior and subverts RVO.  Remove the `&` so these become
local variables.

Signed-off-by: Patrick Williams <patrick@stwcx.xyz>
Change-Id: I8e7da30fddef808dfe7ee323d7f91a7c2a2cdeb6
diff --git a/src/handler.cpp b/src/handler.cpp
index 30b7ba3..5983ad9 100644
--- a/src/handler.cpp
+++ b/src/handler.cpp
@@ -293,7 +293,7 @@
         std::get<endpointsPos>(findEndpoint->second);
     std::unordered_set<std::string> associationSet(association.begin(),
                                                    association.end());
-    const std::vector<InterfaceMapType::value_type>& interfacePairs =
+    const std::vector<InterfaceMapType::value_type> interfacePairs =
         getSubTree(interfaceMap, reqPath, depth, interfaces);
 
     std::vector<InterfaceMapType::value_type> output;
@@ -323,7 +323,7 @@
         std::get<endpointsPos>(findEndpoint->second);
     std::unordered_set<std::string> associationSet(association.begin(),
                                                    association.end());
-    const std::vector<std::string>& paths =
+    const std::vector<std::string> paths =
         getSubTreePaths(interfaceMap, reqPath, depth, interfaces);
 
     std::vector<std::string> output;