Fix mouse face artifacting in NS port

[Po Lu]

I don't know if this is the right thing to do, but this gets rid of the
mouse face box not being drawn correctly on modelines, and text
artifacting on GNUStep when highlighting custom buttons.

Thanks.

diff --git a/src/nsterm.m b/src/nsterm.m
index 77f4ee8ca6..c6f80f8035 100644
--- a/src/nsterm.m
+++ b/src/nsterm.m
@@ -4054,19 +4054,6 @@ overwriting cursor (usually when cursor on a tab) */
   NSRect r[2];
   int n;
   char box_drawn_p = 0;
-
-  struct face *face = s->face;
-  if (s->hl == DRAW_MOUSE_FACE)
-    {
-      face
-       = FACE_FROM_ID_OR_NULL (s->f,
-                               MOUSE_HL_INFO (s->f)->mouse_face_face_id);
-      if (!face)
-       face = FACE_FROM_ID (s->f, MOUSE_FACE_ID);
-    }
-
-  s->face = face;
-
   struct font *font = s->face->font;
   if (! font) font = FRAME_FONT (s->f);