s390/sysinfo,stsi: change return code handling

Change return code handling of the stsi() function:

In case function code 0 was specified the return value is the
current configuration level (already shifted). That way all
the code that actually copied the stsi_0() function can go
away.

Otherwise the return value is 0 (success) or negative to
indicate an error (currently only -EOPNOTSUPP).

Also stsi() is no longer an inline function. The function is
not performance critical, but every caller would generate an
exception table entry for this function.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
diff --git a/arch/s390/kvm/priv.c b/arch/s390/kvm/priv.c
index 60da903..310be61 100644
--- a/arch/s390/kvm/priv.c
+++ b/arch/s390/kvm/priv.c
@@ -211,7 +211,7 @@
 	spin_unlock(&fi->lock);
 
 	/* deal with other level 3 hypervisors */
-	if (stsi(mem, 3, 2, 2) == -ENOSYS)
+	if (stsi(mem, 3, 2, 2))
 		mem->count = 0;
 	if (mem->count < 8)
 		mem->count++;
@@ -259,7 +259,7 @@
 		mem = get_zeroed_page(GFP_KERNEL);
 		if (!mem)
 			goto out_fail;
-		if (stsi((void *) mem, fc, sel1, sel2) == -ENOSYS)
+		if (stsi((void *) mem, fc, sel1, sel2))
 			goto out_mem;
 		break;
 	case 3: