Add a shortcut return in case reallocate has nothing to do. Should reduce a lot of memory thrashing on irrArrays.

git-svn-id: svn://svn.code.sf.net/p/irrlicht/code/trunk@4218 dfc29bdd-3216-0410-991c-e03cc46cb475

include/irrArray.h

@@ -62,6 +62,9 @@ public:
 	/** \param new_size New size of array. */
 	void reallocate(u32 new_size)
 	{
+		if (allocated==new_size)
+			return;
+
 		T* old_data = data;
 
 		data = allocator.allocate(new_size); //new T[new_size];