test/util: Use existing chainman in ::PrepareBlock

Author: dongcarl

src/test/util/mining.cpp

@@ -74,12 +74,12 @@ CTxIn MineBlock(const NodeContext& node, const CScript& coinbase_scriptPubKey)
 std::shared_ptr<CBlock> PrepareBlock(const NodeContext& node, const CScript& coinbase_scriptPubKey)
 {
     auto block = std::make_shared<CBlock>(
-        BlockAssembler{::ChainstateActive(), *Assert(node.mempool), Params()}
+        BlockAssembler{Assert(node.chainman)->ActiveChainstate(), *Assert(node.mempool), Params()}
             .CreateNewBlock(coinbase_scriptPubKey)
             ->block);
 
     LOCK(cs_main);
-    block->nTime = ::ChainActive().Tip()->GetMedianTimePast() + 1;
+    block->nTime = Assert(node.chainman)->ActiveChain().Tip()->GetMedianTimePast() + 1;
     block->hashMerkleRoot = BlockMerkleRoot(*block);
 
     return block;