pstore/ram: Fix error return code in ramoops_probe()

In the if (dev_of_node(dev) && !pdata) path, the "err" may be assigned a
value of 0, so the error return code -EINVAL may be incorrectly set
to 0. To fix set valid return code before calling to goto.

Fixes: 35da6094 ("pstore/ram: add Device Tree bindings")
Signed-off-by: Wang Yufen <wangyufen@huawei.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/1669969374-46582-1-git-send-email-wangyufen@huawei.com

fs/pstore/ram.c

@@ -745,6 +745,7 @@ static int ramoops_probe(struct platform_device *pdev)
 	/* Make sure we didn't get bogus platform data pointer. */
 	if (!pdata) {
 		pr_err("NULL platform data\n");
+		err = -EINVAL;
 		goto fail_out;
 	}
 
@@ -752,6 +753,7 @@ static int ramoops_probe(struct platform_device *pdev)
 			!pdata->ftrace_size && !pdata->pmsg_size)) {
 		pr_err("The memory size and the record/console size must be "
 			"non-zero\n");
+		err = -EINVAL;
 		goto fail_out;
 	}