clang-tidy: Enable readability-simplify-boolean-expr check

This checks for boolean expressions involving boolean constants
and simplifies them to use the appropriate boolean expression
directly.

Signed-off-by: George Liu <liuxiwei@ieisystem.com>
Change-Id: If2316dc52cbd280971f0333ee805b11e1b99d27f
diff --git a/manager/json-config.hpp b/manager/json-config.hpp
index 7d94f20..089879d 100644
--- a/manager/json-config.hpp
+++ b/manager/json-config.hpp
@@ -80,7 +80,7 @@
                 }
                 return false;
             });
-        return it == names.end() ? false : true;
+        return it != names.end();
     }
 
     /**