staging: comedi: usbduxsigma: remove a space before tab

checkpatch.pl reports:

WARNING: please, no space before tabs
+^Ihigh_speed = 0; ^I/* (devpriv->high_speed) */$

Remove the space to avoid the warning.
Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Cc: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>