sof_get_control_data returns negative values even though the return
value is defined unsigned (size_t). So change the return value type to
int and add the data size as pointer argument to sof_get_control_data to
avoid ambiquity in the meaning of the return type.

Fixes: cac974a5 ("ASoC: SOF: topology: use set_get_data in process load")
Reported by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Jaska Uimonen <jaska.uimonen@intel.com>
Link: https://lore.kernel.org/r/20190821211138.14618-1-jaska.uimonen@linux.intel.comSigned-off-by: Mark Brown <broonie@kernel.org>