I had one get stuck like that, so I turned on auto update. That worked. Then I turned it back off. No problems since. If that doesn't work, try a hard reset. Hold the top button and the home button at the same time until the Apple logo appears. Then release.
I don't know if it worked or not. I still have the update notice on the App Store icon. However I went to Chrome and it says I have the update. If I tap the App Store icon it still says "update" with the little red circle with the 1 in it.
I rebooted twice. The App Store icon shows the update circle. I went to settings and checked Chrome under visions and it shows the newest version. But now the update icon still shows the red circle with a 1 in the middle of it. So Chrome is working but the icon and the information show "update all" which is only for Chrome.
I used to have Chrome on both iPhone and iPad, simply because I was familiar with it, having used it as a default browser in my desktops and laptops since it came out several years ago. I always said that its simplicity and speed allowed it to 'breathe new life' into older hardware. I still use it as default on my iMac , again, mostly because familiarity is a good thing. ( and my bookmarks are all intact.)
Having had several issues such as those recently posted about updating, plus several others that to be brief I'll only call 'the good, the bad , and the ugly, I have now uninstalled Mobile Chrome on my iPad and iPhone , and find I really don't miss it. I can only sum up that it wasn't worth the constant fiddling- so I'm getting used to Safari, and it's not bad ! David