tty/hvc_iucv: remove redundant NULL check

Make smatch happy and remove this warning:

drivers/tty/hvc/hvc_iucv.c:1320 hvc_iucv_init() info: redundant null check on
hvc_iucv_filter calling kfree()
Signed-off-by: Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

drivers/tty/hvc/hvc_iucv.c

@@ -1354,8 +1354,7 @@ static int __init hvc_iucv_init(void)
 	mempool_destroy(hvc_iucv_mempool);
 	kmem_cache_destroy(hvc_iucv_buffer_cache);
 out_error:
-	if (hvc_iucv_filter)
-		kfree(hvc_iucv_filter);
+	kfree(hvc_iucv_filter);
 	hvc_iucv_devices = 0; /* ensure that we do not provide any device */
 	return rc;
 }