Gas Optimizations

[code423n4]

Unnecessary Initialisation of variables.

Description:
All data types in solidity have default values and hence they need not be initialized. e.g. uint256 is by default 0. Initializing it in the code unless the logic requires, costs gas fees. This can be avoided easily.

All such variables are listed in a single report for simplicity.
https://github.com/code-423n4/2022-05-aura/blob/main/contracts/AuraBalRewardPool.sol#L35
https://github.com/code-423n4/2022-05-aura/blob/main/contracts/AuraBalRewardPool.sol#L38
https://github.com/code-423n4/2022-05-aura/blob/main/contracts/AuraBalRewardPool.sol#L39
https://github.com/code-423n4/2022-05-aura/blob/main/contracts/AutoLocker.sol#L72
https://github.com/code-423n4/2022-05-aura/blob/main/contracts/AutoLocker.sol#L381
https://github.com/code-423n4/2022-05-aura/blob/main/contracts/AutoLocker.sol#L485
https://github.com/code-423n4/2022-05-aura/blob/main/contracts/AutoLocker.sol#L540
https://github.com/code-423n4/2022-05-aura/blob/main/contracts/AutoLocker.sol#L630
https://github.com/code-423n4/2022-05-aura/blob/main/contracts/AuraMerkleDrop.sol#L29
https://github.com/code-423n4/2022-05-aura/blob/main/contracts/AuraVestedEscrow.sol#L99
https://github.com/code-423n4/2022-05-aura/blob/main/contracts/ExtraRewardsDistributor.sol#L231

Mitigation:
Do not initialize variables unless needed.

[dmvt]

Grouping this with the warden’s gas report, #57