Make the recovery menus wrap.

The real problem is that the recovery UI is sluggish. But being able
to wrap off the top to the bottom halves the maximum distance you'll
have to go.

Change-Id: Ifebe5b818f9c9a1c4187d4ac609422da1f38537f

screen_ui.cpp

@@ -526,8 +526,11 @@ int ScreenRecoveryUI::SelectMenu(int sel) {
     if (show_menu > 0) {
         old_sel = menu_sel;
         menu_sel = sel;
-        if (menu_sel < 0) menu_sel = 0;
-        if (menu_sel >= menu_items) menu_sel = menu_items-1;
+
+        // Wrap at top and bottom.
+        if (menu_sel < 0) menu_sel = menu_items - 1;
+        if (menu_sel >= menu_items) menu_sel = 0;
+
         sel = menu_sel;
         if (menu_sel != old_sel) update_screen_locked();
     }