controller: Fix bugprone-unused-raii

```
/home/andrew/src/openbmc/phosphor-led-sysfs/build/../controller.cpp:143:5: error: object destroyed immediately after creation; did you mean to name the object? [bugprone-unused-raii,-warnings-as-errors]
    sdbusplus::server::manager_t(bus, objPath.c_str());
    ^
                                 give_me_a_name
```

Change-Id: I4225f71874dbabfc315c4ba5d252d0d075868a68
Signed-off-by: Andrew Jeffery <andrew@aj.id.au>
diff --git a/controller.cpp b/controller.cpp
index 723fd7b..517c6ab 100644
--- a/controller.cpp
+++ b/controller.cpp
@@ -139,8 +139,7 @@
     // Get a handle to system dbus.
     auto bus = sdbusplus::bus::new_default();
 
-    // Add systemd object manager.
-    sdbusplus::server::manager_t(bus, objPath.c_str());
+    sdbusplus::server::manager_t manager{bus, objPath.c_str()};
 
     // Create the Physical LED objects for directing actions.
     // Need to save this else sdbusplus destructor will wipe this off.