powerpc/book3s64: Avoid __pte_protnone() check in __pte_flags_need_flush()

This reverts commit 1abce058 ("powerpc/64s: Fix __pte_needs_flush()
false positive warning")

The previous patch dropped the usage of _PAGE_PRIVILEGED with PAGE_NONE.
Hence this check can be dropped.
Signed-off-by: "Aneesh Kumar K.V (IBM)" <aneesh.kumar@kernel.org>
Reviewed-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20231204093638.71503-2-aneesh.kumar@kernel.org

arch/powerpc/include/asm/book3s/64/tlbflush.h

@@ -158,11 +158,6 @@ static inline void flush_tlb_fix_spurious_fault(struct vm_area_struct *vma,
 	 */
 }
 
-static inline bool __pte_protnone(unsigned long pte)
-{
-	return (pte & (pgprot_val(PAGE_NONE) | _PAGE_RWX)) == pgprot_val(PAGE_NONE);
-}
-
 static inline bool __pte_flags_need_flush(unsigned long oldval,
 					  unsigned long newval)
 {
@@ -179,8 +174,8 @@ static inline bool __pte_flags_need_flush(unsigned long oldval,
 	/*
 	 * We do not expect kernel mappings or non-PTEs or not-present PTEs.
 	 */
-	VM_WARN_ON_ONCE(!__pte_protnone(oldval) && oldval & _PAGE_PRIVILEGED);
-	VM_WARN_ON_ONCE(!__pte_protnone(newval) && newval & _PAGE_PRIVILEGED);
+	VM_WARN_ON_ONCE(oldval & _PAGE_PRIVILEGED);
+	VM_WARN_ON_ONCE(newval & _PAGE_PRIVILEGED);
 	VM_WARN_ON_ONCE(!(oldval & _PAGE_PTE));
 	VM_WARN_ON_ONCE(!(newval & _PAGE_PTE));
 	VM_WARN_ON_ONCE(!(oldval & _PAGE_PRESENT));