[LinuxCNC/linuxcnc PR#81] sampler: Update fifo-depth and fifo-full pins even when sampler is not enabled

Currently this pins do not provide live/actual values of fifo.
If halsampler (ULAPI) is reading fifo after sampler is disabled then fifo-depth is altered which is not updated on this pin; Similarly if fifo was full before diabling it and then halsampler emptied it, still sampler will show that fifo is full.

Signed-off-by: Rushabh Loladia rushabh.loladia@gmail.com