staging: ks7010: change some local variables type in ks_sdio_interrupt

Local variables 'status', 'rsize' and 'byte' are declared as
unsigned char and can be declared as u8 which is preferred.
They are being used in ks7010_sdio_readb calls which is already
expected an u8.

Signed-off-by: Sergio Paracuellos <sergio.paracuellos@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>