bugfix: [ #3009 ] possible memory leak in Mathutils

fixed by patch [ #3013 ] patch for memleak in vector
Submitted By: Ken Hughes (khughes)

source/blender/python/api2_2x/matrix.c

@@ -837,5 +837,5 @@ PyObject *newMatrixObject(float *mat, int rowSize, int colSize, int type)
 	}else{ //bad type
 		return NULL;
 	}
-	return (PyObject *) EXPP_incr_ret((PyObject *)self);
+	return (PyObject *) self;
 }