Use temporary buffer for ghc-display

Instead of opening a normal editable buffer (in which editing text does
not make a lot of sense), use Emacs's temporary buffer. Benefits:

   - Read only: Text cannot be modified when focused.
   - Much easier to close (press q), after reading or copying from the
     warning/error.

Signed-off-by: Rohan Jain <crodjer@gmail.com>

elisp/ghc-func.el

@@ -147,7 +147,8 @@
 (defconst ghc-error-buffer-name "*GHC Info*")
 
 (defun ghc-display (fontify ins-func)
-  (let ((buf (get-buffer-create ghc-error-buffer-name)))
+  (let ((buf ghc-error-buffer-name))
+    (with-output-to-temp-buffer buf
       (with-current-buffer buf
         (erase-buffer)
         (funcall ins-func)
@@ -157,7 +158,7 @@
             (turn-off-haskell-font-lock)
           (haskell-font-lock-defaults-create)
           (turn-on-haskell-font-lock)))
-    (display-buffer buf)))
+      (display-buffer buf))))
 
 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;