xen/resume: Fix compile warnings.

linux/drivers/xen/manage.c: In function 'do_suspend':
linux/drivers/xen/manage.c:160:5: warning: 'si.cancelled' may be used uninitialized in this function

Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
diff --git a/drivers/xen/manage.c b/drivers/xen/manage.c
index 9e14ae6..412b96c 100644
--- a/drivers/xen/manage.c
+++ b/drivers/xen/manage.c
@@ -132,6 +132,7 @@
 	err = dpm_suspend_end(PMSG_FREEZE);
 	if (err) {
 		printk(KERN_ERR "dpm_suspend_end failed: %d\n", err);
+		si.cancelled = 0;
 		goto out_resume;
 	}