Regulate 5V to 5V with LM1117?
Adding another regulator is a bad idea since it complicates the power line. 

A better solution is to protect your circuit by shutting off the power when the input voltage exceeds some limit. The circuit below will disconnect the source if the voltage goes over 5.5V. You can make it closer to 5V by reducing the Zener voltage from the shown 5.1V device.







simulate this circuit &ndash; Schematic created using CircuitLab

Description:

When Vin is under 5.5V the zener is off as is Q1. R3 holds the gate of M1 low turning it on as a low resistance. When Vin rises above 5.5V D1 holds the base of Q1 down turning it on which pulls up the voltage on R3 to close to Vin, which turns off M1.