[S390] cleanup facility list handling

Store the facility list once at system startup with stfl/stfle and
reuse the result for all facility tests.

Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
diff --git a/arch/s390/mm/fault.c b/arch/s390/mm/fault.c
index b4aad0c..fe5701e 100644
--- a/arch/s390/mm/fault.c
+++ b/arch/s390/mm/fault.c
@@ -56,12 +56,7 @@
 
 void fault_init(void)
 {
-	unsigned long long facility_list[2];
-
-	if (stfle(facility_list, 2) < 2)
-		return;
-	if ((facility_list[0] & (1ULL << 61)) &&
-	    (facility_list[1] & (1ULL << 52)))
+	if (test_facility(2) && test_facility(75))
 		store_indication = 0xc00;
 }