Remove non-ascii characters from fat code

Remove non-ascii characters from fat code

This code contains some non-ascii characters in comment lines and code.
Most editors do not display those characters properly and editing those
files results always in diffs at these places which are usually not required
to be changed at all. This is error prone.

So, remove those weird characters and replace them by normal C-style
equivalents for which the proper defines were already in the header.

Signed-off-by: Remy Bohmer <linux@bohmer.net>