remoteproc: qcom: wcss: Fix wrong pointer passed to PTR_ERR()

PTR_ERR should access the value just tested by IS_ERR, otherwise
the wrong error code will be returned.

This commit fix it by return 'ret' directly.

Reviewed-by: Dan Carpenter <dan.carpenter@oracle.com>
Fixes: 0af65b9b

 ("remoteproc: qcom: wcss: Add non pas wcss Q6 support for QCS404")
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com>
Link: https://lore.kernel.org/r/20210326024741.841267-1-weiyongjun1@huawei.com
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>