[media] saa7164: better handle error codes

Right now, the driver is doing the right thing for
PVC_ERRORCODE_UNKNOWN and PVC_ERRORCODE_INVALID_CONTROL:
for both, it returns an error code (SAA_ERR_NOT_SUPPORTED).

However, it is printing two error messages instead of one
on those cases.

Fix the logic.
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>

drivers/media/pci/saa7164/saa7164-cmd.c

@@ -506,6 +506,8 @@ int saa7164_cmd_send(struct saa7164_dev *dev, u8 id, enum tmComResCmd command,
 				dprintk(DBGLVL_CMD,
 					"%s() UNKNOWN OR INVALID CONTROL\n",
 					__func__);
+				ret = SAA_ERR_NOT_SUPPORTED;
+				break;
 			default:
 				dprintk(DBGLVL_CMD, "%s() UNKNOWN\n", __func__);
 				ret = SAA_ERR_NOT_SUPPORTED;