x86/xen: cleanup arch/x86/xen/mmu.c

Remove a nested ifdef.
Signed-off-by: Juergen Gross <jgross@suse.com>
Signed-off-by: David Vrabel <david.vrabel@citrix.com>

arch/x86/xen/mmu.c

@@ -1734,10 +1734,8 @@ static void __init xen_map_identity_early(pmd_t *pmd, unsigned long max_pfn)
 		for (pteidx = 0; pteidx < PTRS_PER_PTE; pteidx++, pfn++) {
 			pte_t pte;
 
-#ifdef CONFIG_X86_32
 			if (pfn > max_pfn_mapped)
 				max_pfn_mapped = pfn;
-#endif
 
 			if (!pte_none(pte_page[pteidx]))
 				continue;