random: get rid of GetRand by inlining

src/node/txreconciliation.cpp

@@ -85,7 +85,7 @@ public:
         LOCK(m_txreconciliation_mutex);
 
         LogPrintLevel(BCLog::TXRECONCILIATION, BCLog::Level::Debug, "Pre-register peer=%d\n", peer_id);
-        const uint64_t local_salt{GetRand(UINT64_MAX)};
+        const uint64_t local_salt{FastRandomContext().rand64()};
 
         // We do this exactly once per peer (which are unique by NodeId, see GetNewNodeId) so it's
         // safe to assume we don't have this record yet.