refactor: Make error() return type void

This is needed for the next commit to compile.

src/node/blockstorage.cpp

@@ -1102,9 +1102,10 @@ bool BlockManager::ReadRawBlockFromDisk(std::vector<uint8_t>& block, const FlatF
         filein >> blk_start >> blk_size;
 
         if (blk_start != GetParams().MessageStart()) {
-            return error("%s: Block magic mismatch for %s: %s versus expected %s", __func__, pos.ToString(),
+            error("%s: Block magic mismatch for %s: %s versus expected %s", __func__, pos.ToString(),
                          HexStr(blk_start),
                          HexStr(GetParams().MessageStart()));
+            return false;
         }
 
         if (blk_size > MAX_SIZE) {