staging: comedi: comedi_fops: Shift assignment operator '=' to previous line

Shift '=' assignment operator to the end of previous
line to conform to preferred kernel style line wrapping.
Issue reported by checkpatch CHECK.

Signed-off-by: Nishad Kamdar <nishadkamdar@gmail.com>
Reviewed-by: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>