devm_ioport_map() returns NULL on error but we accidentally check for
error pointers instead.
Fixes: c6acad68eb2d ("platform/mellanox: mlxreg-hotplug: Modify to use a regmap interface")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Acked-by: Vadim Pasternak <vadimp@melanox.com>
Signed-off-by: Darren Hart (VMware) <dvhart@infradead.org>
 
        mlxplat_mlxcpld_regmap_ctx.base = devm_ioport_map(&mlxplat_dev->dev,
                               mlxplat_lpc_resources[1].start, 1);
-       if (IS_ERR(mlxplat_mlxcpld_regmap_ctx.base)) {
-               err = PTR_ERR(mlxplat_mlxcpld_regmap_ctx.base);
+       if (!mlxplat_mlxcpld_regmap_ctx.base) {
+               err = -ENOMEM;
                goto fail_platform_mux_register;
        }