mitigated Unchecked return value Coverity warnings (#5980)

Author: firewave

lib/findtoken.h

@@ -176,7 +176,7 @@ std::vector<T*> findTokensSkipDeadCode(const Library* library,
                                        const Evaluate& evaluate)
 {
     std::vector<T*> result;
-    findTokensSkipDeadCodeImpl(
+    (void)findTokensSkipDeadCodeImpl(
         library,
         start,
         end,
@@ -199,7 +199,7 @@ template<class T, class Predicate, class Evaluate, REQUIRES("T must be a Token c
 T* findTokenSkipDeadCode(const Library* library, T* start, const Token* end, const Predicate& pred, const Evaluate& evaluate)
 {
     T* result = nullptr;
-    findTokensSkipDeadCodeImpl(
+    (void)findTokensSkipDeadCodeImpl(
         library,
         start,
         end,

lib/forwardanalyzer.cpp

@@ -922,6 +922,6 @@ Analyzer::Result valueFlowGenericForward(Token* start, const ValuePtr<Analyzer>&
     if (a->invalid())
         return Analyzer::Result{Analyzer::Action::None, Analyzer::Terminate::Bail};
     ForwardTraversal ft{a, tokenList, errorLogger, settings};
-    ft.updateRecursive(start);
+    (void)ft.updateRecursive(start);
     return Analyzer::Result{ ft.actions, ft.terminate };
 }

lib/valueflow.cpp

@@ -3069,7 +3069,7 @@ struct ValueFlowAnalyzer : Analyzer {
         if (d == Direction::Forward && a.isRead())
             setTokenValue(tok, *value, getSettings());
         if (a.isInconclusive())
-            lowerToInconclusive();
+            (void)lowerToInconclusive();
         if (a.isWrite() && tok->astParent()) {
             writeValue(value, tok, d);
         }