VPP-1459:Ip4 lookup fail when exist prefix cover.

Change-Id: I4ba0aeb65219596475345e42b8cd34019f5594c6
Signed-off-by: mu.duojiao <[email protected]>

Author: mu.duojiao

src/vnet/ip/ip4_mtrie.c

@@ -551,9 +551,7 @@ unset_leaf (ip4_fib_mtrie_t * m,
 
 	  old_ply->leaves[i] =
 	    ip4_fib_mtrie_leaf_set_adj_index (a->cover_adj_index);
-	  old_ply->dst_address_bits_of_leaves[i] =
-	    clib_max (old_ply->dst_address_bits_base,
-		      a->cover_address_length);
+	  old_ply->dst_address_bits_of_leaves[i] = a->cover_address_length;
 
 	  old_ply->n_non_empty_leafs +=
 	    ip4_fib_mtrie_leaf_is_non_empty (old_ply, i);