stream: check ALSA API results as <0 rather than !=0
stream: check ALSA API results as <0 rather than !=0

Most ALSA API functions that return status, declare return value as
either 0 or negative error code. However some functions like
snd_pcm_hw_params_any() return just int. In most cases it's the same 0 or
negative, but as was found in #108, it may return positive values too.

ALSA lib internally uses "< 0" for return value checking.

i-rinat/apulse,i-rinat/apulse