KVM: MMU: use page table level macro

Its much cleaner to use PT_PAGE_TABLE_LEVEL than its numeric value.
Signed-off-by: Davidlohr Bueso <dave@gnu.org>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>

arch/x86/kvm/mmu.c

@@ -3618,7 +3618,7 @@ static bool detect_write_flooding(struct kvm_mmu_page *sp)
 	 * Skip write-flooding detected for the sp whose level is 1, because
 	 * it can become unsync, then the guest page is not write-protected.
 	 */
-	if (sp->role.level == 1)
+	if (sp->role.level == PT_PAGE_TABLE_LEVEL)
 		return false;
 
 	return ++sp->write_flooding_count >= 3;

arch/x86/kvm/paging_tmpl.h

@@ -658,7 +658,7 @@ static gpa_t FNAME(get_level1_sp_gpa)(struct kvm_mmu_page *sp)
 {
 	int offset = 0;
 
-	WARN_ON(sp->role.level != 1);
+	WARN_ON(sp->role.level != PT_PAGE_TABLE_LEVEL);
 
 	if (PTTYPE == 32)
 		offset = sp->role.quadrant << PT64_LEVEL_BITS;