fs: fat_write: fix short name creation.

Truncate file names if the buffer size is exceeded to avoid a buffer
overflow.

Use Sphinx style function description.

Add a TODO comment.

Reported-by: CID 303779
Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
Reviewed-by: Simon Glass <sjg@chromium.org>
1 file changed