[S390] hypfs: Use subcode 6 if subcode 7 is not available

Hypfs never worked on systems that only provide D204 subcode 6.
In these cases we nevertheless used subcode 7. With this fix, we
use subcode 6, if it is available and the system does not provide
subcode 7.
Signed-off-by: NMichael Holzheu <holzheu@linux.vnet.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

arch/s390/hypfs/hypfs_diag.c

@@ -438,7 +438,7 @@ static int diag204_probe(void)
 		}
 		if (diag204((unsigned long)SUBC_STIB6 |
 			    (unsigned long)INFO_EXT, pages, buf) >= 0) {
-			diag204_store_sc = SUBC_STIB7;
+			diag204_store_sc = SUBC_STIB6;
 			diag204_info_type = INFO_EXT;
 			goto out;
 		}