ONOS-5261 BGP link descriptor cannot have multiple 'MultiTopologyId TLV'

Change-Id: I07647eb90e48cdc7008a94387a820f42855b1242
diff --git a/protocols/bgp/bgpio/src/main/java/org/onosproject/bgpio/protocol/linkstate/BgpLinkLSIdentifier.java b/protocols/bgp/bgpio/src/main/java/org/onosproject/bgpio/protocol/linkstate/BgpLinkLSIdentifier.java
index 5fccf6d..0294c9c 100644
--- a/protocols/bgp/bgpio/src/main/java/org/onosproject/bgpio/protocol/linkstate/BgpLinkLSIdentifier.java
+++ b/protocols/bgp/bgpio/src/main/java/org/onosproject/bgpio/protocol/linkstate/BgpLinkLSIdentifier.java
@@ -166,7 +166,7 @@
                 break;
             case BgpAttrNodeMultiTopologyId.ATTRNODE_MULTITOPOLOGY:
                 tlv = BgpAttrNodeMultiTopologyId.read(tempCb);
-                count = count++;
+                count++;
                 //MultiTopologyId TLV cannot repeat more than once
                 if (count > 1) {
                     //length + 4 implies data contains type, length and value