xen/arm: use BUG_ON

Use BUG_ON(x) rather than if(x) BUG();

The semantic patch that fixes this problem is as follows:

// <smpl>
@@ identifier x; @@
-if (x) BUG();
+BUG_ON(x);
// </smpl>

Signed-off-by: Himangi Saraogi <himangi774@gmail.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Acked-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>

arch/arm/xen/enlighten.c

@@ -181,17 +181,15 @@ static void xen_restart(enum reboot_mode reboot_mode, const char *cmd)
 	struct sched_shutdown r = { .reason = SHUTDOWN_reboot };
 	int rc;
 	rc = HYPERVISOR_sched_op(SCHEDOP_shutdown, &r);
-	if (rc)
-		BUG();
+	BUG_ON(rc);
 }
 
 static void xen_power_off(void)
 {
 	struct sched_shutdown r = { .reason = SHUTDOWN_poweroff };
 	int rc;
 	rc = HYPERVISOR_sched_op(SCHEDOP_shutdown, &r);
-	if (rc)
-		BUG();
+	BUG_ON(rc);
 }
 
 static int xen_cpu_notification(struct notifier_block *self,