Fix buffer popping in presentation mode

Author: chrisdone

haskell-presentation-mode.el

@@ -53,8 +53,7 @@ SESSION as the current haskell-session."
           (insert code "\n\n")
           (font-lock-fontify-region point (point))
           (goto-char point))))
-    (if (and (boundp 'haskell-presentation-mode)
-             haskell-presentation-mode)
+    (if (eq major-mode 'haskell-presentation-mode)
         (switch-to-buffer buffer)
       (pop-to-buffer buffer))))