update I/O sched Kconfig help texts - CFQ is now default, not AS.

Change I/O scheduler description to correctly show CFQ as being the default
scheduler and not the anticipatory scheduler that previously was default.

Signed-off-by: Jesper Juhl <jesper.juhl@gmail.com>
Signed-off-by: Adrian Bunk <bunk@stusta.de>
1 file changed