tests: Fix the FIB UT

Type: test

The FIB UT fails in debug mode because there is no string associated woth its fib_node_type_t.
Change the tests to register their own type, which will give it a name.

Signed-off-by: Neale Ranns <neale@graphiant.com>
Change-Id: I36e546718faa7241c088494cbae10939aca51d5a
diff --git a/src/vnet/fib/fib_node.h b/src/vnet/fib/fib_node.h
index b6089ec..6639c39 100644
--- a/src/vnet/fib/fib_node.h
+++ b/src/vnet/fib/fib_node.h
@@ -53,8 +53,7 @@
     /**
      * Marker. New types before this one. leave the test last.
      */
-    FIB_NODE_TYPE_TEST,
-    FIB_NODE_TYPE_LAST = FIB_NODE_TYPE_TEST,
+    FIB_NODE_TYPE_LAST = FIB_NODE_TYPE_ENTRY_TRACK,
 } __attribute__ ((packed)) fib_node_type_t;
 
 #define FIB_NODE_TYPE_MAX (FIB_NODE_TYPE_LAST + 1)