bnxt_en: Add page_pool_destroy() during RX ring cleanup.

Add page_pool_destroy() in bnxt_free_rx_rings() during normal RX ring
cleanup, as Ilias has informed us that the following commit has been
merged:

1da4bbeffe ("net: core: page_pool: add user refcnt and reintroduce page_pool_destroy")

The special error handling code to call page_pool_free() can now be
removed.  bnxt_free_rx_rings() will always be called during normal
shutdown or any error paths.

Fixes: 322b87ca55 ("bnxt_en: add page_pool support")
Cc: Ilias Apalodimas <ilias.apalodimas@linaro.org>
Cc: Andy Gospodarek <gospo@broadcom.com>
Signed-off-by: Michael Chan <michael.chan@broadcom.com>
Acked-by: Andy Gospodarek <gospo@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/broadcom/bnxt/bnxt.c

@@ -2500,6 +2500,7 @@ static void bnxt_free_rx_rings(struct bnxt *bp)
 		if (xdp_rxq_info_is_reg(&rxr->xdp_rxq))
 			xdp_rxq_info_unreg(&rxr->xdp_rxq);
 
+		page_pool_destroy(rxr->page_pool);
 		rxr->page_pool = NULL;
 
 		kfree(rxr->rx_tpa);
@@ -2560,19 +2561,14 @@ static int bnxt_alloc_rx_rings(struct bnxt *bp)
 			return rc;
 
 		rc = xdp_rxq_info_reg(&rxr->xdp_rxq, bp->dev, i);
-		if (rc < 0) {
-			page_pool_free(rxr->page_pool);
-			rxr->page_pool = NULL;
+		if (rc < 0)
 			return rc;
-		}
 
 		rc = xdp_rxq_info_reg_mem_model(&rxr->xdp_rxq,
 						MEM_TYPE_PAGE_POOL,
 						rxr->page_pool);
 		if (rc) {
 			xdp_rxq_info_unreg(&rxr->xdp_rxq);
-			page_pool_free(rxr->page_pool);
-			rxr->page_pool = NULL;
 			return rc;
 		}