dsp: bugfix for memory leak in error handling path

Add extra goto label in order to free memory in case program
failed to acquire memory through callback_node. With the
original code, there might be a situation where the memory
acquired by client_info_node will not be freed, thus causing
possible memory leak.

Change-Id: If5c8a4bdfbed4ada57a7563e9e212dc9aa7caab0
Signed-off-by: Jinjuan Qiu <jinjqiu@codeaurora.org>