10090 rt2860_free_rx_ring doesn't need to check for NULL array

@@ -1,9 +1,10 @@
 /*
  * Copyright 2017 Gary Mills
  * Copyright 2010 Sun Microsystems, Inc.  All rights reserved.
  * Use is subject to license terms.
+ * Copyright (c) 2018, Joyent, Inc.
  */
 
 /*
  * Copyright (c) 2007, 2008
  *      Damien Bergamini <damien.bergamini@free.fr>

@@ -898,16 +899,15 @@
 
         if (ring->rxd != NULL)
                 rt2860_free_dma_mem(&ring->rxdesc_dma);
 
         count = RT2860_RX_RING_COUNT;
-        if (ring->data != NULL) {
+
                 for (i = 0; i < count; i++) {
                         data = &ring->data[i];
                         rt2860_free_dma_mem(&data->rxbuf_dma);
                 }
-        }
 }
 
 static int
 rt2860_alloc_tx_pool(struct rt2860_softc *sc)
 {