lp: correct rules for whether an unknown field can be ignored

Add TLV-TYPE to exception output for unignorable unknown and unrepeatable fields

refs #3884

Change-Id: I52c6cc2b6b5363432d8cc5bf60407ccf6ece7dc0
diff --git a/tests/unit-tests/lp/packet.t.cpp b/tests/unit-tests/lp/packet.t.cpp
index 0a7f1d5..2dd055e 100644
--- a/tests/unit-tests/lp/packet.t.cpp
+++ b/tests/unit-tests/lp/packet.t.cpp
@@ -275,7 +275,7 @@
     0x64, 0x0c, // LpPacket
           0x52, 0x01, // FragIndex
                 0x00,
-          0xfd, 0x03, 0x23, 0x01, // unknown TLV-TYPE 803 (ignored)
+          0xfd, 0x03, 0x24, 0x01, // unknown TLV-TYPE 804 (ignored)
                 0x02,
           0x50, 0x02, // Fragment
                 0x03, 0xe8,