mwifiex: remove unneeded kfree(NULL);

The previous if statement means this that pointer is NULL so there
is no need to free it.
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Acked-by: Bing Zhao <bzhao@marvell.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

drivers/net/wireless/mwifiex/pcie.c

@@ -386,7 +386,6 @@ static int mwifiex_pcie_create_txbd_ring(struct mwifiex_adapter *adapter)
 	card->txbd_ring_vbase = kzalloc(card->txbd_ring_size, GFP_KERNEL);
 	if (!card->txbd_ring_vbase) {
 		dev_err(adapter->dev, "Unable to allocate buffer for txbd ring.\n");
-		kfree(card->txbd_ring_vbase);
 		return -1;
 	}
 	card->txbd_ring_pbase = virt_to_phys(card->txbd_ring_vbase);