qcom: bam_dma: Delete useless kfree code

The parameter of kfree function is NULL, so kfree code is useless, delete it.
Therefore, goto expression is no longer needed, so simplify it.

Signed-off-by: Zheng Yongjun <zhengyongjun3@huawei.com>
Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Link: https://lore.kernel.org/r/20201216130649.13979-1-zhengyongjun3@huawei.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>