ALSA: asihpi: Simplify error handling in PCM substream setup

Refactor error handling in the PCM substream setup to combine redundant
checks and improve code readability. Free the dpcm structure and return
appropriate error codes (-EBUSY for HPI_ERROR_OBJ_ALREADY_OPEN, -EIO
for other errors) in a single block.

Signed-off-by: Jihed Chaibi <jihed.chaibi.dev@gmail.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>