ocaml: Memory leak: Free roots array along handle close path.

(cherry picked from commit c5dbb1e63a)

ocaml/guestfs_c.c

@@ -82,6 +82,7 @@ guestfs_finalize (value gv)
       caml_remove_global_root (roots[i]);
       free (roots[i]);
     }
+    free (roots);
 
     caml_remove_global_root (v);
     free (v);