Documentation/cdrom: fix German sharp s in LaTex

Apparently the LaTex abbreviation for the German "sharp s" (ß)
(Unicode U+00DF) has changed from {\sz} to {\ss}.  With {\sz},
I get this error at line 1016 (line number after another patch):

! Undefined control sequence.
l.1016 ...nel~2.0.  Further thanks to Heiko Ei{\sz
                                                  }feldt,

This is fixed by changing the {\sz} to {\ss}.
Signed-off-by: NRandy Dunlap <rdunlap@infradead.org>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

Documentation/cdrom/cdrom-standard.tex

@@ -1013,7 +1013,7 @@ taken over the torch in maintaining \cdromc\ and integrating much
 \cdrom-related code in the 2.1-kernel.  Thanks to Scott Snyder and
 Gerd Knorr, who were the first to implement this interface for SCSI
 and IDE-CD drivers and added many ideas for extension of the data
-structures relative to kernel~2.0.  Further thanks to Heiko Ei{\sz}feldt,
+structures relative to kernel~2.0.  Further thanks to Heiko Ei{\ss}feldt,
 Thomas Quinot, Jon Tombs, Ken Pizzini, Eberhard M\"onkeberg and Andrew
 Kroll, the \linux\ \cdrom\ device driver developers who were kind
 enough to give suggestions and criticisms during the writing. Finally