staging: comedi: ni_mio_common: fix the ni_write[blw]() functions

Memory mapped io (dev->mmio) should not also be writing to the ioport
(dev->iobase) registers. Add the missing 'else' to these functions.

Fixes: 0953ee4a ("staging: comedi: ni_mio_common: checkpatch.pl cleanup (else not useful)")
Cc: <stable@vger.kernel.org> # 3.17+
Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Reviewed-by: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>