rect.el: Suppress superfluous "Mark set" message from push-mark.

lisp/ChangeLog

@@ -1,3 +1,8 @@
+2015-02-18  Kelly Dean  <kelly@prtime.org>
+
+	* rect.el (rectangle-mark-mode):
+	Suppress superfluous "Mark set" message from push-mark.
+
 2015-02-18  Kelly Dean  <kelly@prtime.org>
 
 	* help-mode.el (help-go-back, help-go-forward, help-follow):

lisp/rect.el

@@ -586,8 +586,7 @@ Activates the region if needed.  Only lasts until the region is deactivated."
     (add-hook 'deactivate-mark-hook
               (lambda () (rectangle-mark-mode -1)))
     (unless (region-active-p)
-      (push-mark)
-      (activate-mark)
+      (push-mark (point) t t)
       (message "Mark set (rectangle mode)"))))
 
 (defun rectangle-exchange-point-and-mark (&optional arg)