refactor: Add simple clang-tidy readability checks (#6556)

This change enables the following clang-tidy checks:
-  readability-avoid-nested-conditional-operator,
-  readability-avoid-return-with-void-value,
-  readability-braces-around-statements,
-  readability-const-return-type,
-  readability-container-contains,
-  readability-container-size-empty,
-  readability-else-after-return,
-  readability-make-member-function-const,
-  readability-redundant-casting,
-  readability-redundant-inline-specifier,
-  readability-redundant-member-init,
-  readability-redundant-string-init,
-  readability-reference-to-constructed-temporary,
-  readability-static-definition

src/libxrpl/server/LoadFeeTrack.cpp

@@ -4,6 +4,7 @@
 #include <xrpl/protocol/Units.h>
 #include <xrpl/server/LoadFeeTrack.h>
 
+#include <algorithm>
 #include <cstdint>
 
 namespace xrpl {
@@ -19,14 +20,12 @@ LoadFeeTrack::raiseLocalFee()
     std::uint32_t const origFee = localTxnLoadFee_;
 
     // make sure this fee takes effect
-    if (localTxnLoadFee_ < remoteTxnLoadFee_)
-        localTxnLoadFee_ = remoteTxnLoadFee_;
+    localTxnLoadFee_ = std::max(localTxnLoadFee_, remoteTxnLoadFee_);
 
     // Increase slowly
     localTxnLoadFee_ += (localTxnLoadFee_ / lftFeeIncFraction);
 
-    if (localTxnLoadFee_ > lftFeeMax)
-        localTxnLoadFee_ = lftFeeMax;
+    localTxnLoadFee_ = std::min(localTxnLoadFee_, lftFeeMax);
 
     if (origFee == localTxnLoadFee_)
         return false;
@@ -45,8 +44,7 @@ LoadFeeTrack::lowerLocalFee()
     // Reduce slowly
     localTxnLoadFee_ -= (localTxnLoadFee_ / lftFeeDecFraction);
 
-    if (localTxnLoadFee_ < lftNormalFee)
-        localTxnLoadFee_ = lftNormalFee;
+    localTxnLoadFee_ = std::max(localTxnLoadFee_, lftNormalFee);
 
     if (origFee == localTxnLoadFee_)
         return false;