[PATCH] mm/arm: pgtable: remove young bit check for pte_valid_user

[Brian Ruley]

On Apr 13, Will Deacon wrote:
> 
> Brian, can you try something like 588a513d3425?
> 
> Will
> 
> [1] https://lore.kernel.org/all/YJGHApOCXl811VK3@arm.com/

Applied the fix and so far so good. We're going to run `stress-ng'
tests overnight to be sure. In the meanwhile, I'll see if I can add
some instrumentation to verify this is the bug we're seeing.

BR,
Brian