media: pulse8-cec: handle possible ping error

Handle (and warn about) possible error waiting for MSGCODE_PING result.

Found by Linux Verification Center (linuxtesting.org) with SVACE.

Signed-off-by: Dmitry Antipov <[e-mail]>
Signed-off-by: Hans Verkuil <[e-mail]>
Signed-off-by: Mauro Carvalho Chehab <[e-mail]>

drivers/media/cec/usb/pulse8/pulse8-cec.c

···
 
 	mutex_lock(&pulse8->lock);
 	cmd = MSGCODE_PING;
-	pulse8_send_and_wait(pulse8, &cmd, 1,
-			     MSGCODE_COMMAND_ACCEPTED, 0);
+	if (pulse8_send_and_wait(pulse8, &cmd, 1,
+				 MSGCODE_COMMAND_ACCEPTED, 0)) {
+		dev_warn(pulse8->dev, "failed to ping EEPROM\n");
+		goto unlock;
+	}
 
 	if (pulse8->vers < 2)
 		goto unlock;