Firmware: Fix warning
Firmware: Fix warning

Canaan-Creative/Avalon-nano,Canaan-Creative/Avalon-nano,Canaan-Creative/Avalon-nano,Canaan-Creative/Avalon-nano,Canaan-Creative/Avalon-nano,Canaan-Creative/Avalon-nano,Canaan-Creative/Avalon-nano,Canaan-Creative/Avalon-nano