Internals: Fix cppcheck warnings; add VL_DANGLING. No functional change.

src/V3CoverageJoin.cpp

@@ -93,7 +93,7 @@ private:
 		    UINFO(8,"   new "<<removep->incp()->declp()<<endl);
 		    // Mark the found node as a duplicate of the first node
 		    // (Not vice-versa as we have the iterator for the found node)
-		    removep->unlinkFrBack();  pushDeletep(removep); removep=NULL;
+		    removep->unlinkFrBack();  pushDeletep(removep); VL_DANGLING(removep);
 		    // Remove node from comparison so don't hit it again
 		    hashed.erase(dupit);
 		    ++m_statToggleJoins;