Use (next-error-internal) instead of (next-error 0) error visiting

This is just a minor fix/optimization. `(next-error-internal)` better
matches the behavior of `compile-goto-error` in the presence of other
next-error capable because it avoids calling `next-error-find-buffer`.

This is related to #62

haskell-interactive-mode.el

@@ -153,7 +153,7 @@ Key bindings:
   "Handle the return key."
   (interactive)
   (if (haskell-interactive-at-compile-message)
-      (next-error 0)
+      (next-error-internal)
     (haskell-interactive-handle-line)))
 
 (defun haskell-interactive-mode-space (n)