Internals: Fix remaining cppcheck errors (#6319)

Fixed the non const-related issue and added suppressions for the const
ones. With that `make cppcheck` should be clean.

src/V3Table.cpp

@@ -213,12 +213,14 @@ private:
         if (chkvis.isCoverage()) {
             chkvis.clearOptimizable(nodep, "Table removes coverage points");
         }
+        // cppcheck-suppress knownConditionTrueFalse // set by TableSimulateVisitor
         if (!m_outWidthBytes || !m_inWidthBits) {
             chkvis.clearOptimizable(nodep, "Table has no outputs");
         }
         if (chkvis.instrCount() < TABLE_MIN_NODE_COUNT) {
             chkvis.clearOptimizable(nodep, "Table has too few nodes involved");
         }
+        // cppcheck-suppress knownConditionTrueFalse
         if (space > TABLE_MAX_BYTES) {
             chkvis.clearOptimizable(nodep, "Table takes too much space");
         }