powerpc/64e: Fix wrong test in __ptep_test_and_clear_young()

Commit 45201c879469 ("powerpc/nohash: Remove hash related code from
nohash headers.") replaced:

if ((pte_val(*ptep) & (_PAGE_ACCESSED | _PAGE_HASHPTE)) == 0)
return 0;

By:

if (pte_young(*ptep))
return 0;

But it should be:

if (!pte_young(*ptep))
return 0;

Fix it.

Fixes: 45201c879469 ("powerpc/nohash: Remove hash related code from nohash headers.")
Signed-off-by: Christophe Leroy <[e-mail]>
Signed-off-by: Michael Ellerman <[e-mail]>
Link: https://msgid.link/8bb7f064[e-mail]

arch/powerpc/include/asm/nohash/64/pgtable.h

···
 {
 	unsigned long old;
 
-	if (pte_young(*ptep))
+	if (!pte_young(*ptep))
 		return 0;
 	old = pte_update(mm, addr, ptep, _PAGE_ACCESSED, 0, 0);
 	return (old & _PAGE_ACCESSED) != 0;