You are required by the IRS to file form 8889 if you have either contributions to or distributions from your HSA in 2017. It's not a matter of getting a credit. It is the IRS's verification that the pre-tax contributions are being spent for medical purposes and if not you will be taxed. Also, if you made excess contributions, the IRS will collect tax.
Note that the IRS has copies of your W-2 and of any 1099-SA forms sent to you. If the IRS has documentation that you are required to file a form 8889 and you don't, then the IRS assumes that your contributions and your distributions were taxable and will likely send you a letter asking for taxes, penalties, and interest.
Your contributions and distributions are normally not supposed to be taxable, so the IRS presumption that they are taxable because you did not provide the information.
