[media] rc: transmit on device which does not support it should fail

Currently write() will return 0 if an IR device does not support sending.

Signed-off-by: Sean Young <[e-mail]>
Signed-off-by: Mauro Carvalho Chehab <[e-mail]>

drivers/media/rc/ir-lirc-codec.c

···
 	struct lirc_codec *lirc;
 	struct rc_dev *dev;
 	unsigned int *txbuf; /* buffer with values to transmit */
-	ssize_t ret = 0;
+	ssize_t ret = -EINVAL;
 	size_t count;
 
 	lirc = lirc_get_pdata(file);