syslinux: properly fix shortcut caret appearing in menu entries

this reverts commit 0cef87ff though retaining the 'advanced options' menu entry using a label rather than a title.

despite having done a lot of testing back in 2015 with my bootloader improvements, i notice now that in fact the syslinux caret fix has an undesired side effect of modifying the title displayed above the menus. it does not help that the text embedded into the splash overlaps with this menu title; perhaps this explains why i missed this problem back in 2015.

purely reverting the implemented fix solves this title problem, but restores the caret problem to the advanced options menu (in menu.cfg); however that menu was using a caret in a title entry, unlike everywhere else where they are only used with labels, which must have been the original source of the problem all along. ensuring that this menu uses a label instead of a title in this reversion leaves everything working correctly afaict.

Gbp-Dch: Ignore