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.

Change-Id: I4ad7ec4ddfa4cfe9a0cf0d569d3d81c478c1776a
Signed-off-by: Pavithra Barithaya <pavithrabarithaya07@gmail.com>
diff --git a/chassis_state_manager.cpp b/chassis_state_manager.cpp
index 189f2de..05cc784 100644
--- a/chassis_state_manager.cpp
+++ b/chassis_state_manager.cpp
@@ -280,7 +280,7 @@
                     continue;
                 }
 
-                if (std::get<bool>(properties["IsPresent"]) != true)
+                if (!std::get<bool>(properties["IsPresent"]))
                 {
                     // There is a UPS detected but it is not officially
                     // "present" yet. Monitor it for state change.