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

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

Change-Id: I79d7e4486bd0ea5f5b9b5a1644af99384e41e251
Signed-off-by: Pavithra Barithaya <pavithrabarithaya07@gmail.com>
diff --git a/.clang-tidy b/.clang-tidy
index 24f78f0..1dec9a7 100644
--- a/.clang-tidy
+++ b/.clang-tidy
@@ -247,6 +247,7 @@
 readability-redundant-member-init,
 readability-redundant-preprocessor,
 readability-redundant-smartptr-get,
+readability-simplify-boolean-expr,
 readability-simplify-subscript-expr,
 readability-static-definition-in-anonymous-namespace,
 readability-string-compare,
diff --git a/activation.cpp b/activation.cpp
index 8f4c4c0..cd44cc0 100644
--- a/activation.cpp
+++ b/activation.cpp
@@ -206,7 +206,7 @@
     // can be re-programmed.
     parent.createUpdateableAssociation(path);
 
-    if (Activation::checkApplyTimeImmediate() == true)
+    if (Activation::checkApplyTimeImmediate())
     {
         info("Image Active and ApplyTime is immediate; rebooting BMC.");
         Activation::rebootBmc();
diff --git a/image_verify.cpp b/image_verify.cpp
index 4d874b4..12e938e 100644
--- a/image_verify.cpp
+++ b/image_verify.cpp
@@ -147,7 +147,7 @@
         bool valid;
         // Verify the MANIFEST and publickey file using available
         // public keys and hash on the system.
-        if (false == systemLevelVerify())
+        if (!systemLevelVerify())
         {
             error("System level Signature Validation failed");
             return false;
@@ -211,7 +211,7 @@
             }
         }
 
-        if (verifyFullImage() == false)
+        if (!verifyFullImage())
         {
             error("Image full file Signature Validation failed");
             return false;
@@ -436,7 +436,7 @@
 
         // Verify the signature.
         valid = verifyFile(file, sigFile, publicKeyPath, hashType);
-        if (valid == false)
+        if (!valid)
         {
             error("Image file Signature Validation failed on {PATH}", "PATH",
                   bmcImage);
diff --git a/msl_verify.cpp b/msl_verify.cpp
index cf05ea3..d578281 100644
--- a/msl_verify.cpp
+++ b/msl_verify.cpp
@@ -120,11 +120,7 @@
 {
     std::string msl = getMinimumVersion();
     std::string mslRegex{REGEX_BMC_MSL};
-    if (!msl.empty() && !mslRegex.empty())
-    {
-        return true;
-    }
-    return false;
+    return !msl.empty() && !mslRegex.empty();
 }
 
 std::string minimum_ship_level::getMinimumVersion()