[PATCH] xen/manage: correct return value check on xenbus_scanf()

[Jan Beulich]

Only a positive return value indicates success.

Signed-off-by: Jan Beulich <jbeulich@xxxxxxxx>
---
 drivers/xen/manage.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- 4.7-rc6-xenbus_scanf.orig/drivers/xen/manage.c
+++ 4.7-rc6-xenbus_scanf/drivers/xen/manage.c
@@ -275,7 +275,7 @@ static void sysrq_handler(struct xenbus_
 	err = xenbus_transaction_start(&xbt);
 	if (err)
 		return;
-	if (!xenbus_scanf(xbt, "control", "sysrq", "%c", &sysrq_key)) {
+	if (xenbus_scanf(xbt, "control", "sysrq", "%c", &sysrq_key) <= 0) {
 		pr_err("Unable to read sysrq code in control/sysrq\n");
 		xenbus_transaction_end(xbt, 1);
 		return;