drivers/net/ns8382x.c: Fix compile warning

Fix this:
ns8382x.c: In function 'ns8382x_initialize':
ns8382x.c:352:13: warning: assignment from incompatible pointer type

Signed-off-by: Joe Hershberger <joe.hershberger@ni.com>
diff --git a/drivers/net/ns8382x.c b/drivers/net/ns8382x.c
index 11863fe..cfe1f34 100644
--- a/drivers/net/ns8382x.c
+++ b/drivers/net/ns8382x.c
@@ -258,8 +258,7 @@
 static void ns8382x_init_rxd(struct eth_device *dev);
 static void ns8382x_set_rx_mode(struct eth_device *dev);
 static void ns8382x_check_duplex(struct eth_device *dev);
-static int ns8382x_send(struct eth_device *dev, volatile void *packet,
-			int length);
+static int ns8382x_send(struct eth_device *dev, void *packet, int length);
 static int ns8382x_poll(struct eth_device *dev);
 static void ns8382x_disable(struct eth_device *dev);
 
@@ -735,8 +734,7 @@
 /* Function: ns8382x_send
  * Description: transmits a packet and waits for completion or timeout.
  * Returns:   void.  */
-static int
-ns8382x_send(struct eth_device *dev, volatile void *packet, int length)
+static int ns8382x_send(struct eth_device *dev, void *packet, int length)
 {
 	u32 i, status = 0;
 	vu_long tx_stat = 0;