Cleanup macro magic (#5270)

* Cleanup macro magic

Signed-off-by: Oliver Tale-Yazdi <oliver.tale-yazdi@parity.io>

* Make sign_call infallible

Signed-off-by: Oliver Tale-Yazdi <oliver.tale-yazdi@parity.io>

* Fix build

Signed-off-by: Oliver Tale-Yazdi <oliver.tale-yazdi@parity.io>

* cargo update -p sp-io

Signed-off-by: Oliver Tale-Yazdi <oliver.tale-yazdi@parity.io>

Co-authored-by: parity-processbot <>