There should be no need to amend. The amount that you recharacterized, information that you should have included in the explanation statement with your 2016 tax return, is the only important detail regarding a recharacterization and that did not change.
One thing to note: A recharacterization contribution is not permitted to be made to a 403(b). The only permissible way to accomplish getting the money back to a 403(b) is to recharacterize from the Roth IRA to a traditional IRA by trustee-to-trustee transfer, then perform a rollover from the traditional IRA to the 403(b). If you did this, you should have a 2017 Form 1099-R, code G if done by direct rollover, to be reported on your 2017 tax return.