Make prefixes optional in listInstanceToString

For libyang, I need a version without prefixes. Side note: the call in
SysrepoAccess would also work without the prefixes, but I'm going to
leave them, so that the functionality doesn't change.

Change-Id: I0c309288ec39ec3f5e835050fb73a5238ebe8e33
diff --git a/src/sysrepo_access.cpp b/src/sysrepo_access.cpp
index d8a64da..7b9cb7a 100644
--- a/src/sysrepo_access.cpp
+++ b/src/sysrepo_access.cpp
@@ -313,7 +313,7 @@
         if (m_schema->nodeType(source) == yang::NodeTypes::LeafList) {
             destPathStr = stripLeafListValueFromPath(source) + "[.='" + leafDataToString(relative.m_path.at(".")) + "']";
         } else {
-            destPathStr = stripLastListInstanceFromPath(source) + instanceToString(m_schema->dataNodeFromPath(source)->node_module()->name(), relative.m_path);
+            destPathStr = stripLastListInstanceFromPath(source) + instanceToString(relative.m_path, m_schema->dataNodeFromPath(source)->node_module()->name());
         }
     }
     m_session->move_item(source.c_str(), toSrMoveOp(move), destPathStr.c_str());