staging: comedi: s526: fix if() check in s526_gpct_winsn()

This if() check was flipped from a test for valid data params
to a test for invalid params.

As pointed out by Dan Carpenter, the orignal test was:

	if ((data[1] > data[0]) && (data[0] > 0)) {

the flipped test should be:

	if (data[1] <= data[0]) ...

Add the missing '='.

Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Cc: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>