Add clang-tidy to phosphor-led-manager

This commit enables clang-tidy and adds few tidy checks.

Signed-off-by: George Liu <liuxiwei@ieisystem.com>
Change-Id: I3a7b41545fef4c726b56aeab3e4b4000dfcac32f
diff --git a/manager/lamptest/lamptest.cpp b/manager/lamptest/lamptest.cpp
index b306e51..8b98fbc 100644
--- a/manager/lamptest/lamptest.cpp
+++ b/manager/lamptest/lamptest.cpp
@@ -219,7 +219,7 @@
         fs::create_directories(ledDirectory);
     }
 
-    std::ofstream(lampTestIndicator.c_str());
+    std::ofstream ofs(lampTestIndicator.c_str());
 
     // Set all the Physical action to On for lamp test
     for (const auto& path : physicalLEDPaths)