Where did the button to hang up the phone from the lock screen go on iOS 10
Solution 1:
On the lock screen in iOS 10, a swipe right gets you to that new lock info screen (this used to get you call controls), a swipe left gets you the camera. I had the same reaction, how do I get to call controls?!?
It turns out, you just need to tap the phone number or contact name displayed on the lock screen, and you will get the call controls. This makes sense, in hindsight, as the swipe right now has a new behavior, but it wasn't obvious to me either.
Also, the sleep/wake physical button hands up the phone, so that's often easier than using the screen in many situations.
Solution 2:
As long as you are not on speakerphone, you can always end the call using the power button. Just press it once.
By the way, this feature exists since 2007 when Steve Jobs revealed the original iPhone.