Improve use of constref which is now possible due to the API change in...

Improve use  of constref which is now possible due to the API change in irrMap. Suggestion made by JVr

git-svn-id: svn://svn.code.sf.net/p/irrlicht/code/trunk@3999 dfc29bdd-3216-0410-991c-e03cc46cb475

include/irrMap.h

@@ -903,7 +903,7 @@ class map
 
 		while(pNode!=0)
 		{
-			KeyType key(pNode->getKey());
+			const KeyType& key=pNode->getKey();
 
 			if (keyToFind == key)
 				return pNode;
@@ -1031,10 +1031,10 @@ class map
 		else
 		{
 			Node* pNode = Root;
-			KeyType keyNew = newNode->getKey();
+			const KeyType& keyNew = newNode->getKey();
 			while (pNode)
 			{
-				KeyType key(pNode->getKey());
+				const KeyType& key=pNode->getKey();
 
 				if (keyNew == key)
 				{