ASoC: Resolve use after free in listen sound client

Updated get_param_payload buffer ptr to NULL
after free to avoid use after free issue.

Change-Id: I86da8c12a0bdccce690f67b037198b67640e339b
Signed-off-by: Soumya Managoli <quic_c_smanag@quicinc.com>
(cherry picked from commit f10c5fa0)