fixup! fixup! Fix #8260 Improve check: Pointer calculation result not null

Author: francois-berder

lib/checkcondition.cpp

@@ -1782,15 +1782,15 @@ void CheckCondition::checkPointerAdditionResultNotNull()
             if (tok->isExpandedMacro())
                 continue;
 
-            const Token *calcToken = NULL, *exprToken = NULL;
+            const Token *calcToken = nullptr, *exprToken = nullptr;
             if (tok->astOperand1()->str() == "+") {
                 calcToken = tok->astOperand1();
                 exprToken = tok->astOperand2();
             } else if (tok->astOperand2()->str() == "+") {
                 calcToken = tok->astOperand2();
                 exprToken = tok->astOperand1();
             } else {
-                const Token *pointerToken = NULL;
+                const Token *pointerToken = nullptr;
                 if (tok->astOperand1()->variable() && tok->astOperand1()->variable()->isPointer())
                     pointerToken = tok->astOperand1();
                 else if (tok->astOperand2()->variable() && tok->astOperand2()->variable()->isPointer())