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>
diff --git a/drivers/net/wireless/rayctl.h b/drivers/net/wireless/rayctl.h
index d7646f2..3c3b98b1 100644
--- a/drivers/net/wireless/rayctl.h
+++ b/drivers/net/wireless/rayctl.h
@@ -566,9 +566,9 @@
     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 {