purescript-indentation.el: replace killing/make-local with just setq-local

There's no reason for killing (I even checked other major modes), and
the make-local-variable may be replaced by just setq-local.

Author: Hi-Angel

purescript-indentation.el

@@ -126,14 +126,12 @@ set and deleted as if they were real tabs.  It supports
 autofill-mode."
   :lighter " Ind"
   :keymap purescript-indentation-mode-map
-  (kill-local-variable 'indent-line-function)
-  (kill-local-variable 'normal-auto-fill-function)
   (when purescript-indentation-mode
     (setq max-lisp-eval-depth (max max-lisp-eval-depth 600)) ;; set a higher limit for recursion
-    (set (make-local-variable 'indent-line-function)
-         'purescript-indentation-indent-line)
-    (set (make-local-variable 'normal-auto-fill-function)
-         'purescript-indentation-auto-fill-function)))
+    (setq-local indent-line-function
+                #'purescript-indentation-indent-line)
+    (setq-local normal-auto-fill-function
+                #'purescript-indentation-auto-fill-function)))
 
 ;;;###autoload
 (defun turn-on-purescript-indentation ()