The constructor of UStbMinting contract does not set ustb, it checks whether _assets[k] is address(ustb) from L187
https://github.com/code-423n4/2024-11-ethena-labs/blob/main/contracts/ustb/UStbMinting.sol#L187
Because initial value ustb is 0, _assets[k] == address(ustb) is same as _assets[k] == address(0).
This means _assets[k] == address(ustb) is an unnecessary check.
Sets the initial ustb in the constructor of the UStbMinting contract.
