Macro cleanup: PROTO

Regarding dict_lookup() in eval.c: both definitions are the same, the
only difference being the spacing between the indirection operator and
the indentation level.

src/nvim/edit.c

@@ -5800,7 +5800,7 @@ void set_last_insert(int c)
   last_insert_skip = 0;
 }
 
-#if defined(EXITFREE) || defined(PROTO)
+#if defined(EXITFREE)
 void free_last_insert(void)
 {
   free(last_insert);