staging: comedi: remove this_board macro in the serial2002 driver
The 'thisboard' macro depends on having a local variable with
a magic name. The CodingStyle document suggests not doing this
to avoid confusion. Remove the macro and use the comedi_board()
inline helper to get the dev->board_ptr information.
Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com> Cc: Ian Abbott <abbotti@mev.co.uk> Cc: Mori Hess <fmhess@users.sourceforge.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>