media: ddbridge: only register frontends in fe2 if fe is not NULL

Smatch reported:

  drivers/media/pci/ddbridge/ddbridge-core.c:1602 dvb_input_attach() error: we previously assumed 'dvb->fe' could be null (see line 1595)

dvb->fe2 will ever only be populated when dvb->fe is set. So only handle
registration of dvb->fe2 when dvb->fe got set beforehand by moving the
registration into the "if (dvb->fe)" conditional.

Cc: Ralph Metzler <rjkm@metzlerbros.de>
Signed-off-by: Daniel Scheller <d.scheller@gmx.net>
Tested-by: Richard Scobie <r.scobie@clear.net.nz>
Tested-by: Jasmin Jessich <jasmin@anw.at>
Tested-by: Dietmar Spingler <d_spingler@freenet.de>
Tested-by: Manfred Knick <Manfred.Knick@t-online.de>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>

drivers/media/pci/ddbridge/ddbridge-core.c

@@ -1506,23 +1506,25 @@ static int dvb_input_attach(struct ddb_input *input)
 		return 0;
 	}
 	dvb->attached = 0x30;
+
 	if (dvb->fe) {
 		if (dvb_register_frontend(adap, dvb->fe) < 0)
 			return -ENODEV;
+
+		if (dvb->fe2) {
+			if (dvb_register_frontend(adap, dvb->fe2) < 0)
+				return -ENODEV;
+			dvb->fe2->tuner_priv = dvb->fe->tuner_priv;
+			memcpy(&dvb->fe2->ops.tuner_ops,
+			       &dvb->fe->ops.tuner_ops,
+			       sizeof(struct dvb_tuner_ops));
+		}
 	}
-	if (dvb->fe2) {
-		if (dvb_register_frontend(adap, dvb->fe2) < 0)
-			return -ENODEV;
-		dvb->fe2->tuner_priv = dvb->fe->tuner_priv;
-		memcpy(&dvb->fe2->ops.tuner_ops,
-		       &dvb->fe->ops.tuner_ops,
-		       sizeof(struct dvb_tuner_ops));
-	}
+
 	dvb->attached = 0x31;
 	return 0;
 }
 
-
 static int port_has_encti(struct ddb_port *port)
 {
 	struct device *dev = port->dev->dev;