vxlan: fix a typo.

Use eXtensible and not eXtensiable in the comment on top.

Signed-off-by: Rami Rosen <ramirose@gmail.com>
Acked-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/vxlan.c b/drivers/net/vxlan.c
index 0c4d0f4..3d0bf66 100644
--- a/drivers/net/vxlan.c
+++ b/drivers/net/vxlan.c
@@ -1,5 +1,5 @@
 /*
- * VXLAN: Virtual eXtensiable Local Area Network
+ * VXLAN: Virtual eXtensible Local Area Network
  *
  * Copyright (c) 2012 Vyatta Inc.
  *