[media] drxk_hard: fix the return code from an error handler

While it is very unlikely, if the number of parameters for
QAMDemodulatorCommand is not 2 or 4, status become undefined:

/home/hans/work/build/v4l-dvb-git/drivers/media/dvb-frontends/drxk_hard.c: In function ‘QAMDemodulatorCommand’:
/home/hans/work/build/v4l-dvb-git/drivers/media/dvb-frontends/drxk_hard.c:5452:5: warning: ‘status’ may be used uninitialized in this function [-Wuninitialized]
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

drivers/media/dvb-frontends/drxk_hard.c

@@ -5446,6 +5446,7 @@ static int QAMDemodulatorCommand(struct drxk_state *state,
 	} else {
 		printk(KERN_WARNING "drxk: Unknown QAM demodulator parameter "
 			"count %d\n", numberOfParameters);
+		status = -EINVAL;
 	}
 
 error: