PPC32: use VM_FAULT_* names instead of numbers.

arch/ppc/mm/fault.c

@@ -189,16 +189,18 @@ void do_page_fault(struct pt_regs *regs, unsigned long address,
 	 */
  survive:
         switch (handle_mm_fault(mm, vma, address, is_write)) {
-        case 1:
+        case VM_FAULT_MINOR:
                 current->min_flt++;
                 break;
-        case 2:
+        case VM_FAULT_MAJOR:
                 current->maj_flt++;
                 break;
-        case 0:
+        case VM_FAULT_SIGBUS:
                 goto do_sigbus;
-        default:
+        case VM_FAULT_OOM:
                 goto out_of_memory;
+	default:
+		BUG();
 	}
 
 	up_read(&mm->mmap_sem);