staging: comedi: me4000: add namespace to reset_board()

Rename reset_board() to me4000_reset() so it has namespace associated
with this driver. Change it's return type to void, it always succeeds.

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>