s390/scm: use inline dummy functions

Convert the defines for the !CONFIG_SCM* stuff to static inline
functions.

Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
diff --git a/drivers/s390/cio/chsc.h b/drivers/s390/cio/chsc.h
index 662dab4..227e05f 100644
--- a/drivers/s390/cio/chsc.h
+++ b/drivers/s390/cio/chsc.h
@@ -157,7 +157,7 @@
 #ifdef CONFIG_SCM_BUS
 int scm_update_information(void);
 #else /* CONFIG_SCM_BUS */
-#define scm_update_information() 0
+static inline int scm_update_information(void) { return 0; }
 #endif /* CONFIG_SCM_BUS */