fib: constify the adjacency in the rewrite nodes

Type: refactor

Signed-off-by: Neale Ranns <nranns@cisco.com>
Change-Id: I3aad20b35d89fc541fdf185096d71ca12b09a6e2
diff --git a/src/vnet/adj/rewrite.h b/src/vnet/adj/rewrite.h
index c2084ea..5c1d24e 100644
--- a/src/vnet/adj/rewrite.h
+++ b/src/vnet/adj/rewrite.h
@@ -154,7 +154,7 @@
   vnet_rewrite_get_data_internal (&((rw).rewrite_header), sizeof ((rw).rewrite_data))
 
 always_inline void
-_vnet_rewrite_one_header (vnet_rewrite_header_t * h0,
+_vnet_rewrite_one_header (const vnet_rewrite_header_t * h0,
 			  void *packet0, int most_likely_size)
 {
   /* 0xfefe => poisoned adjacency => crash */
@@ -172,8 +172,8 @@
 }
 
 always_inline void
-_vnet_rewrite_two_headers (vnet_rewrite_header_t * h0,
-			   vnet_rewrite_header_t * h1,
+_vnet_rewrite_two_headers (const vnet_rewrite_header_t * h0,
+			   const vnet_rewrite_header_t * h1,
 			   void *packet0, void *packet1, int most_likely_size)
 {
   /* 0xfefe => poisoned adjacency => crash */