[S390] chsc headers userspace cleanup

Kernel headers shouldn't expose functions to userspace.

Cc: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Adrian Bunk <bunk@kernel.org>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
diff --git a/include/asm-s390/schid.h b/include/asm-s390/schid.h
index 5017ffa..7bdc0fe 100644
--- a/include/asm-s390/schid.h
+++ b/include/asm-s390/schid.h
@@ -10,6 +10,7 @@
 	__u32 sch_no : 16;
 } __attribute__ ((packed, aligned(4)));
 
+#ifdef __KERNEL__
 
 /* Helper function for sane state of pre-allocated subchannel_id. */
 static inline void
@@ -25,4 +26,6 @@
 	return !memcmp(schid1, schid2, sizeof(struct subchannel_id));
 }
 
+#endif /* __KERNEL__ */
+
 #endif /* ASM_SCHID_H */