node-SDK: Fix hfc getChain with create true error

The function getChain(chainName, create) uses
an undefined variable "name" when calling
chain = newChain(name).
https://jira.hyperledger.org/browse/FAB-128

Change-Id: Ic8b255bd2888bc3d90f3f09322aacb4bf1687f69
Signed-off-by: Caroline Daughtrey <cdaughtr@us.ibm.com>

sdk/node/src/hfc.ts

@@ -2692,7 +2692,7 @@ export function newChain(name) {
 export function getChain(chainName, create) {
     let chain = _chains[chainName];
     if (!chain && create) {
-        chain = newChain(name);
+        chain = newChain(chainName);
     }
     return chain;
 }