Consider making _calculateFees inline to save gas

[code423n4]

Handle

WatchPug

Vulnerability details

https://github.com/code-423n4/2021-11-nested/blob/f646002b692ca5fa3631acfff87dda897541cf41/contracts/NestedFactory.sol#L553-L559

/// @dev Calculate the fees for a specific user and amount (1%)
/// @param _user The user address
/// @param _amount The amount
/// @return The fees amount
function _calculateFees(address _user, uint256 _amount) private view returns (uint256) {
    return _amount / 100;
}

The function _calculateFees() is a rather simple function, replacing it with inline expression _amount / 100 can save some gas.

[maximebrugel]

Also, making this function inline will remove the unused parameter _user.
Issues pointing this unused parameter (or change to pure) will be linked here.

[alcueca]

Also comments are wrong (#194)