[L-02] Redundant Check in 'certified' Function

[softstackio]

Likelihood: High

Description
In the 'certified' function of the CertifierHbbft contract, there is a redundant check that unnecessarily complicates the code and may lead to confusion. The function first checks if 'stakingAddress == address(0)' and returns false if so. However, it then always returns 'stakingAddress != address(0)', which is essentially the inverse of the first check. This redundancy does not affect the functionality but reduces code clarity and efficiency.

Recommendation:
Simplify the 'certified' function by removing the redundant check. The function can be rewritten as follows:

function certified(address _who) external view returns (bool) {
   if (_certified[_who]) {
       return true;
   }
   address stakingAddress =
validatorSetContract.stakingByMiningAddress(_who);
   return stakingAddress != address(0);
}