ray_cs: Fix array bounds warnings.

rx_msg is defined to have a 1 entry array at the end, so gcc warns:

drivers/net/wireless/ray_cs.c: In function ‘rx_authenticate’:
drivers/net/wireless/ray_cs.c:2436:3: warning: array subscript is above array bounds [-Warray-bounds]
drivers/net/wireless/ray_cs.c:2436:3: warning: array subscript is above array bounds [-Warray-bounds]
drivers/net/wireless/ray_cs.c:2436:3: warning: array subscript is above array bounds [-Warray-bounds]
drivers/net/wireless/ray_cs.c:2436:3: warning: array subscript is above array bounds [-Warray-bounds]
drivers/net/wireless/ray_cs.c:2436:3: warning: array subscript is above array bounds [-Warray-bounds]
drivers/net/wireless/ray_cs.c:2439:15: warning: array subscript is above array bounds [-Warray-bounds]
drivers/net/wireless/ray_cs.c:2452:16: warning: array subscript is above array bounds [-Warray-bounds]
drivers/net/wireless/ray_cs.c:2453:18: warning: array subscript is above array bounds [-Warray-bounds]
drivers/net/wireless/ray_cs.c:2453:32: warning: array subscript is above array bounds [-Warray-bounds]

Use a zero length array and rename to "ray_rx_msg" to make sure we hit all
of the necessary cases.
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/wireless/ray_cs.c

@@ -2426,7 +2426,7 @@ static void rx_authenticate(ray_dev_t *local, struct rcs __iomem *prcs,
 			    unsigned int pkt_addr, int rx_len)
 {
 	UCHAR buff[256];
-	struct rx_msg *msg = (struct rx_msg *)buff;
+	struct ray_rx_msg *msg = (struct ray_rx_msg *) buff;
 
 	del_timer(&local->timer);
 
@@ -2513,7 +2513,7 @@ static void rx_deauthenticate(ray_dev_t *local, struct rcs __iomem *prcs,
 			      unsigned int pkt_addr, int rx_len)
 {
 /*  UCHAR buff[256];
-    struct rx_msg *msg = (struct rx_msg *)buff;
+    struct ray_rx_msg *msg = (struct ray_rx_msg *) buff;
 */
 	pr_debug("Deauthentication frame received\n");
 	local->authentication_state = UNAUTHENTICATED;

drivers/net/wireless/rayctl.h

@@ -566,9 +566,9 @@ struct phy_header {
     UCHAR hdr_3;
     UCHAR hdr_4;
 };
-struct rx_msg {
+struct ray_rx_msg {
     struct mac_header mac;
-    UCHAR  var[1];
+    UCHAR  var[0];
 };
 
 struct tx_msg {