ASoC: nuc900: Fix a loop timeout test

We should be finishing the loop with timeout set to zero but because
this is a post-op we finish with timeout == -1.

Fixes: 1082e270

 ("ASoC: NUC900/audio: add nuc900 audio driver support")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Mark Brown <broonie@kernel.org>