Bluetooth: qca: Fix error code in qca_read_fw_build_info()

Return -ENOMEM on allocation failure.  Don't return success.

Fixes: cda0d6a1

 ("Bluetooth: qca: fix info leak when fetching fw build id")
Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org>
Reviewed-by: Johan Hovold <johan+linaro@kernel.org>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>