soc: qcom: cmd-db: Fix an error code in cmd_db_dev_probe()
The memremap() function doesn't return error pointers, it returns NULL.
This code is returning "ret = PTR_ERR(NULL);" which is success, but it
should return -ENOMEM.
Fixes: 312416d9171a ("drivers: qcom: add command DB driver") Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org> Signed-off-by: Andy Gross <andy.gross@linaro.org>