Check for AssertLockNotHeld in EnforceBestChainLock() instead of just having a comment in code

Author: UdjinM6

src/llmq/quorums_chainlocks.cpp

@@ -488,6 +488,9 @@ bool CChainLocksHandler::IsTxSafeForMining(const uint256& txid)
 // This should also not be called from validation signals, as this might result in recursive calls
 void CChainLocksHandler::EnforceBestChainLock()
 {
+    AssertLockNotHeld(cs);
+    AssertLockNotHeld(cs_main);
+
     CChainLockSig clsig;
     const CBlockIndex* pindex;
     const CBlockIndex* currentBestChainLockBlockIndex;