s390/mm: mark private defines for vm_fault_t as such

This fixes several sparse warnings for fault.c:

arch/s390/mm/fault.c:336:36: warning: restricted vm_fault_t degrades to integer
arch/s390/mm/fault.c:573:23: warning: incorrect type in assignment (different base types)
arch/s390/mm/fault.c:573:23:    expected restricted vm_fault_t [usertype] fault
arch/s390/mm/fault.c:573:23:    got int
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>

arch/s390/mm/fault.c

@@ -44,11 +44,11 @@
 #define __SUBCODE_MASK 0x0600
 #define __PF_RES_FIELD 0x8000000000000000ULL
 
-#define VM_FAULT_BADCONTEXT	0x010000
-#define VM_FAULT_BADMAP		0x020000
-#define VM_FAULT_BADACCESS	0x040000
-#define VM_FAULT_SIGNAL		0x080000
-#define VM_FAULT_PFAULT		0x100000
+#define VM_FAULT_BADCONTEXT	((__force vm_fault_t) 0x010000)
+#define VM_FAULT_BADMAP		((__force vm_fault_t) 0x020000)
+#define VM_FAULT_BADACCESS	((__force vm_fault_t) 0x040000)
+#define VM_FAULT_SIGNAL		((__force vm_fault_t) 0x080000)
+#define VM_FAULT_PFAULT		((__force vm_fault_t) 0x100000)
 
 enum fault_type {
 	KERNEL_FAULT,