coins: use hashBlock setter internally for CCoinsViewCache methods

Co-authored-by: l0rinc <pap.lorinc@gmail.com>

src/coins.cpp

@@ -7,6 +7,7 @@
 #include <consensus/consensus.h>
 #include <logging.h>
 #include <random.h>
+#include <uint256.h>
 #include <util/trace.h>
 
 TRACEPOINT_SEMAPHORE(utxocache, add);
@@ -250,7 +251,7 @@ void CCoinsViewCache::BatchWrite(CoinsViewCacheCursor& cursor, const uint256& ha
             }
         }
     }
-    hashBlock = hashBlockIn;
+    SetBestBlock(hashBlockIn);
 }
 
 void CCoinsViewCache::Flush(bool will_reuse_cache)
@@ -278,7 +279,7 @@ void CCoinsViewCache::Reset() noexcept
 {
     cacheCoins.clear();
     cachedCoinsUsage = 0;
-    hashBlock.SetNull();
+    SetBestBlock(uint256::ZERO);
 }
 
 void CCoinsViewCache::Uncache(const COutPoint& hash)