[S390] fix _TIF_SINGLE_STEP definition

_TIF_SINGLE_STEP is incorrectly defined as 1<<TIF_FREEZE.  Fix it.

Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
diff --git a/arch/s390/include/asm/thread_info.h b/arch/s390/include/asm/thread_info.h
index 1a5dbb6..f9a9a10 100644
--- a/arch/s390/include/asm/thread_info.h
+++ b/arch/s390/include/asm/thread_info.h
@@ -117,7 +117,7 @@
 #define _TIF_SIE		(1<<TIF_SIE)
 #define _TIF_POLLING_NRFLAG	(1<<TIF_POLLING_NRFLAG)
 #define _TIF_31BIT		(1<<TIF_31BIT)
-#define _TIF_SINGLE_STEP	(1<<TIF_FREEZE)
+#define _TIF_SINGLE_STEP	(1<<TIF_SINGLE_STEP)
 #define _TIF_FREEZE		(1<<TIF_FREEZE)
 
 #ifdef CONFIG_64BIT