[S390] pfault: Fix alignment of parameter list.

Make sure parameter list of the pfault token function is eight byte
aligned. Otherwise we can get specification exceptions.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

arch/s390/mm/fault.c

@@ -468,7 +468,7 @@ typedef struct {
 	__u64 refselmk;
 	__u64 refcmpmk;
 	__u64 reserved;
-} __attribute__ ((packed)) pfault_refbk_t;
+} __attribute__ ((packed, aligned(8))) pfault_refbk_t;
 
 int pfault_init(void)
 {