[media] drxk: Does not unlock mutex if sanity check failed in scu_command()

If sanity check fails in scu_command(), goto error leads to unlock of
an unheld mutex. The check should not fail in reality, but it nevertheless
worth fixing.

Found by Linux Driver Verification project (linuxtesting.org).
Signed-off-by: Alexey Khoroshilov <khoroshilov@ispras.ru>
Cc: stable@kernel.org
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

drivers/media/dvb/frontends/drxk_hard.c

@@ -1520,8 +1520,10 @@ static int scu_command(struct drxk_state *state,
 	dprintk(1, "\n");
 
 	if ((cmd == 0) || ((parameterLen > 0) && (parameter == NULL)) ||
-	    ((resultLen > 0) && (result == NULL)))
-		goto error;
+	    ((resultLen > 0) && (result == NULL))) {
+		printk(KERN_ERR "drxk: Error %d on %s\n", status, __func__);
+		return status;
+	}
 
 	mutex_lock(&state->mutex);