It's a common practice to make resource release functions be NULL-aware.
Make ptp_ocp_unregister_ext() NULL-aware.

Reviewed-by: Vadim Fedorenko <vadim.fedorenko@linux.dev>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
---
 drivers/ptp/ptp_ocp.c | 24 ++++++++++--------------
 1 file changed, 10 insertions(+), 14 deletions(-)

diff --git a/drivers/ptp/ptp_ocp.c b/drivers/ptp/ptp_ocp.c
index 49bad0f83779..1fd2243e0f9f 100644
--- a/drivers/ptp/ptp_ocp.c
+++ b/drivers/ptp/ptp_ocp.c
@@ -2225,6 +2225,9 @@ ptp_ocp_ts_enable(void *priv, u32 req, bool enable)
 static void
 ptp_ocp_unregister_ext(struct ptp_ocp_ext_src *ext)
 {
+	if (!ext)
+		return;
+
 	ext->info->enable(ext, ~0, false);
 	pci_free_irq(ext->bp->pdev, ext->irq_vec, ext);
 	kfree(ext);
@@ -4555,21 +4558,14 @@ ptp_ocp_detach(struct ptp_ocp *bp)
 	ptp_ocp_detach_sysfs(bp);
 	ptp_ocp_attr_group_del(bp);
 	timer_delete_sync(&bp->watchdog);
-	if (bp->ts0)
-		ptp_ocp_unregister_ext(bp->ts0);
-	if (bp->ts1)
-		ptp_ocp_unregister_ext(bp->ts1);
-	if (bp->ts2)
-		ptp_ocp_unregister_ext(bp->ts2);
-	if (bp->ts3)
-		ptp_ocp_unregister_ext(bp->ts3);
-	if (bp->ts4)
-		ptp_ocp_unregister_ext(bp->ts4);
-	if (bp->pps)
-		ptp_ocp_unregister_ext(bp->pps);
+	ptp_ocp_unregister_ext(bp->ts0);
+	ptp_ocp_unregister_ext(bp->ts1);
+	ptp_ocp_unregister_ext(bp->ts2);
+	ptp_ocp_unregister_ext(bp->ts3);
+	ptp_ocp_unregister_ext(bp->ts4);
+	ptp_ocp_unregister_ext(bp->pps);
 	for (i = 0; i < 4; i++)
-		if (bp->signal_out[i])
-			ptp_ocp_unregister_ext(bp->signal_out[i]);
+		ptp_ocp_unregister_ext(bp->signal_out[i]);
 	for (i = 0; i < __PORT_COUNT; i++)
 		if (bp->port[i].line != -1)
 			serial8250_unregister_port(bp->port[i].line);
-- 
2.50.1