fix: use correct CGo syntax for Free (#478)

Author: Thegaram

rollup/circuitcapacitychecker/impl.go

@@ -73,7 +73,7 @@ func (ccc *CircuitCapacityChecker) ApplyTransaction(traces *types.BlockTrace) (*
 	log.Debug("start to check circuit capacity for tx", "id", ccc.ID, "TxHash", traces.Transactions[0].TxHash)
 	rawResult := C.apply_tx(C.uint64_t(ccc.ID), tracesStr)
 	defer func() {
-		C.free(rawResult)
+		C.free(unsafe.Pointer(rawResult))
 	}()
 	log.Debug("check circuit capacity for tx done", "id", ccc.ID, "TxHash", traces.Transactions[0].TxHash)
 
@@ -122,7 +122,7 @@ func (ccc *CircuitCapacityChecker) ApplyBlock(traces *types.BlockTrace) (*types.
 	log.Debug("start to check circuit capacity for block", "id", ccc.ID, "blockNumber", traces.Header.Number, "blockHash", traces.Header.Hash())
 	rawResult := C.apply_block(C.uint64_t(ccc.ID), tracesStr)
 	defer func() {
-		C.free(rawResult)
+		C.free(unsafe.Pointer(rawResult))
 	}()
 	log.Debug("check circuit capacity for block done", "id", ccc.ID, "blockNumber", traces.Header.Number, "blockHash", traces.Header.Hash())