APPS crashes randomly due to invalid memory allocation
in q6asm_audio_client_buf_free_contiguous.
Added check to return error if memory allocation size is 0.
Change-Id: I40f49aa147d513b29b56224a5ee77ccbb2dcc110
CRs-Fixed: 2285272
Signed-off-by: Soumya Managoli <smanag@codeaurora.org>