Change variable scopes

cppcheck correctly notes that a lot of our variables can be declared at
more specific scopes, and in every case, it seems to be correct.

Tested: Redfish service validator passes.  Unit test coverage on others.

Signed-off-by: Ed Tanous <edtanous@google.com>
Change-Id: Ia4414410d0e8f74a3bd40fdc0e0232450d1a6416
diff --git a/redfish-core/lib/sensors.hpp b/redfish-core/lib/sensors.hpp
index 3cd4379..627ba7e 100644
--- a/redfish-core/lib/sensors.hpp
+++ b/redfish-core/lib/sensors.hpp
@@ -531,11 +531,10 @@
             return;
         }
         const std::string* chassisPath = nullptr;
-        std::string chassisName;
         for (const std::string& chassis : chassisPaths)
         {
             sdbusplus::message::object_path path(chassis);
-            chassisName = path.filename();
+            std::string chassisName = path.filename();
             if (chassisName.empty())
             {
                 BMCWEB_LOG_ERROR << "Failed to find '/' in " << chassis;