Staging: fbtft: removed trailing whitespace

The following patch fixes the checkpatch.pl warning:
Removed all trailing whitespace in fb_s6d1121.c
Signed-off-by: NYeliz Taneroglu <yeliztaneroglu@gmail.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>