powerpc/mm/slice: remove radix calls to the slice code

This is a tidy up which removes radix MMU calls into the slice
code.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

arch/powerpc/mm/hugetlbpage.c

@@ -565,10 +565,12 @@ unsigned long hugetlb_get_unmapped_area(struct file *file, unsigned long addr,
 unsigned long vma_mmu_pagesize(struct vm_area_struct *vma)
 {
 #ifdef CONFIG_PPC_MM_SLICES
-	unsigned int psize = get_slice_psize(vma->vm_mm, vma->vm_start);
 	/* With radix we don't use slice, so derive it from vma*/
-	if (!radix_enabled())
+	if (!radix_enabled()) {
+		unsigned int psize = get_slice_psize(vma->vm_mm, vma->vm_start);
+
 		return 1UL << mmu_psize_to_shift(psize);
+	}
 #endif
 	if (!is_vm_hugetlb_page(vma))
 		return PAGE_SIZE;