MPLS performance improvments.

 1 - Quad loop lookup and label imposition.
 2 - optimise imposition for the 1 label case
 3 - input gets TTL from header directly (no byte swap)

Change-Id: I59204c9e5d134b0df75d7afa43e360f946d1ffe7
Signed-off-by: Neale Ranns <nranns@cisco.com>
diff --git a/src/vnet/mpls/error.def b/src/vnet/mpls/error.def
index de8b966..34a4652 100644
--- a/src/vnet/mpls/error.def
+++ b/src/vnet/mpls/error.def
@@ -18,11 +18,11 @@
 mpls_error (NONE, "no error")
 mpls_error (UNKNOWN_PROTOCOL, "unknown protocol")
 mpls_error (UNSUPPORTED_VERSION, "unsupported version")
-mpls_error (PKTS_DECAP, "MPLS-GRE input packets decapsulated")
-mpls_error (PKTS_ENCAP, "MPLS-GRE output packets encapsulated")
-mpls_error (NO_LABEL, "MPLS-GRE no label for fib/dst")
-mpls_error (TTL_EXPIRED, "MPLS-GRE ttl expired")
-mpls_error (S_NOT_SET, "MPLS-GRE s-bit not set")
+mpls_error (PKTS_DECAP, "MPLS input packets decapsulated")
+mpls_error (PKTS_ENCAP, "MPLS output packets encapsulated")
+mpls_error (NO_LABEL, "MPLS no label for fib/dst")
+mpls_error (TTL_EXPIRED, "MPLS ttl expired")
+mpls_error (S_NOT_SET, "MPLS s-bit not set")
 mpls_error (BAD_LABEL, "invalid FIB id in label")
 mpls_error (NOT_IP4, "non-ip4 packets dropped")
 mpls_error (DISALLOWED_FIB, "disallowed FIB id")