From: Jan Beulich <JBeulich@suse.com>
Date: Fri, 3 Feb 2017 08:54:05 +0000 (-0700)
Subject: xen/manage: correct return value check on xenbus_scanf()
X-Git-Tag: v4.11-rc1~136^2~16
X-Git-Url: http://git.samba.org/samba.git/?p=sfrench%2Fcifs-2.6.git;a=commitdiff_plain;h=4fed1b125eb6252bde478665fc05d4819f774fa8

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

A negative return value indicates an error; in fact the function at
present won't ever return zero.

Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Juergen Gross <jgross@suse.com>
Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
---

diff --git a/drivers/xen/manage.c b/drivers/xen/manage.c
index 26e5e8507f03..357a8db859c9 100644
--- a/drivers/xen/manage.c
+++ b/drivers/xen/manage.c
@@ -277,7 +277,7 @@ static void sysrq_handler(struct xenbus_watch *watch, const char **vec,
 	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;