ASoC: msm: qdsp6v2: Add check for DSP status before using the size

Add the check for the DSP return status code before using the size
to copy the data into the destination buffer. If the DSP returns
an error, the size should not be used, an error should be returned
instead.

CRs-fixed: 668331
Change-Id: Ia27de9f59fbd14ac5c829ba3f1d89a0175f7a7a1
Signed-off-by: Damir Didjusto <damird@codeaurora.org>