alsa: Do not use snd_pcm_hw_params_set_rate_near()

alsa: Do not use snd_pcm_hw_params_set_rate_near()

snd_pcm_hw_params_set_rate_near() will try to use the samplerate closest to the
given value, potentially starting the acquisition with a different samplerate
than the one specified.

Instead, use snd_pcm_hw_params_set_rate(). It will return an error if the
samplerate is not supported by the hardware, which is arguably better than
collecting data with a different samplerate than the one specified.

Signed-off-by: Alexandru Gagniuc <redacted>