s390/fault: use _ASCE_ORIGIN instead of PAGE_MASK

When masking an ASCE to get its origin use the corresponding define
instead of the unrelated PAGE_MASK.
This doesn't fix a bug since both masks are identical.
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

arch/s390/mm/fault.c

@@ -130,7 +130,7 @@ static int bad_address(void *p)
 
 static void dump_pagetable(unsigned long asce, unsigned long address)
 {
-	unsigned long *table = __va(asce & PAGE_MASK);
+	unsigned long *table = __va(asce & _ASCE_ORIGIN);
 
 	pr_alert("AS:%016lx ", asce);
 	switch (asce & _ASCE_TYPE_MASK) {