message: Avoid assigning () to _ and for missing error propagation
diff: @@ -40,7 +40,6 @@ pub fn do_read<S: Storage, Q: Querier>(ctx: &mut Ctx, key_ptr: u32) -> VmResult<
  let key = read_region(ctx, key_ptr, MAX_LENGTH_DB_KEY)?;
  let ffi_result = with_storage_from_context::<S, Q, _, _>(ctx, |store| Ok(store.get(&key)))?;
  -
  let value = match ffi_result {
  Ok((value, gas_info)) => {
  process_gas_info::<S, Q>(ctx, gas_info)?;
  @@ -74,8 +73,7 @@ pub fn do_write<S: Storage, Q: Querier>(
  let ffi_result =
  with_storage_from_context::<S, Q, _, _>(ctx, |store| Ok(store.set(&key, &value)))?;
  -
  - let _ = match ffi_result {
  + match ffi_result {
  Ok(((), gas_info)) => {
  process_gas_info::<S, Q>(ctx, gas_info)?;
  Ok(())
  @@ -95,9 +93,9 @@ pub fn do_remove<S: Storage, Q: Querier>(ctx: &mut Ctx, key_ptr: u32) -> VmResul
  }
  let key = read_region(ctx, key_ptr, MAX_LENGTH_DB_KEY)?;
  - let ffi_result = with_storage_from_context::<S, Q, _, _>(ctx, |store| Ok(store.remove(&key)))?;
  - let _ = match ffi_result {
  + let ffi_result = with_storage_from_context::<S, Q, _, _>(ctx, |store| Ok(store.remove(&key)))?;
  + match ffi_result {
  Ok(((), gas_info)) => {
  process_gas_info::<S, Q>(ctx, gas_info)?;
  Ok(())
  @@ -106,7 +104,7 @@ pub fn do_remove<S: Storage, Q: Querier>(ctx: &mut Ctx, key_ptr: u32) -> VmResul
  process_gas_info::<S, Q>(ctx, gas_info)?;
  Err(VmError::from(err))
  }
  - };
  + }?;
  Ok(())
  }
  @@ -189,7 +187,6 @@ pub fn do_query_chain<S: Storage, Q: Querier>(ctx: &mut Ctx, request_ptr: u32) -
  let ffi_result =
  with_querier_from_context::<S, Q, _, _>(ctx, |querier| Ok(querier.raw_query(&request)))?;
  -
  let res = match ffi_result {
  Ok((res, gas_info)) => {
  process_gas_info::<S, Q>(ctx, gas_info)?;
  @@ -217,10 +214,10 @@ pub fn do_scan<S: Storage + 'static, Q: Querier>(
  let order: Order = order
  .try_into()
  .map_err(|_| CommunicationError::invalid_order(order))?;
  +
  let ffi_result = with_storage_from_context::<S, Q, _, _>(ctx, |store| {
  Ok(store.range(start.as_deref(), end.as_deref(), order))
  })?;
  -
  let iterator_id = match ffi_result {
  Ok((iterator, gas_info)) => {
  process_gas_info::<S, Q>(ctx, gas_info)?;
  @@ -240,7 +237,6 @@ pub fn do_scan<S: Storage + 'static, Q: Querier>(
  pub fn do_next<S: Storage, Q: Querier>(ctx: &mut Ctx, iterator_id: u32) -> VmResult<u32> {
  let ffi_result =
  with_iterator_from_context::<S, Q, _, _>(ctx, iterator_id, |iter| Ok(iter.next()))?;
  -
  let kv = match ffi_result {
  Ok((kv, gas_info)) => {
  process_gas_info::<S, Q>(ctx, gas_info)?;
  