consensus: use the public constant MaxGasLimit to check the header.GasLimit

[jovijovi]

Use the constant maxGasLimit to check the header.GasLimit to avoid creating new variables repeatedly.
It has been tested and passed in the development environment.

[holiman]

The way you did it, instead of being three 'magic' values spread out in the codebase, it's instead three constants spread out in the codebase. Not sure if that's (a lot) better, really?
If we want it a constant, perhaps better to make it a public constant somewhere.

[jovijovi]

The way you did it, instead of being three 'magic' values spread out in the codebase, it's instead three constants spread out in the codebase. Not sure if that's (a lot) better, really?

If we want it a constant, perhaps better to make it a public constant somewhere.

I thought of that. But there seems to be no place for public constants in the consensus code files. Maybe we can add a new consensus/const.go file to save public constants.

[fjl]

We usually keep such constants in package params.

[jovijovi]

We usually keep such constants in package params.

You're right, I got it. I'll keep the constant MaxGasLimit in params/protocol_params.go.