Staging: comedi: amcc_s5933: "no space before tabs" coding style fixes.

Fixed a coding style issues.
Signed-off-by: NMichal Kwiatkowski <michaelflowersky@geekingspree.com>
Reviewed-by: NIan Abbott <abbotti@mev.co.uk>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>