[S390] etr/stp: put correct per cpu variable

Fix this compile error in linux-next:

arch/s390/kernel/time.c: In function 'get_sync_clock':
arch/s390/kernel/time.c:337: error: 'clock_sync_sync' undeclared (first use in this function)

Gets exposed because the new per cpu code references the variable
passed to put_cpu_var. This was not a real bug.
Reported-by: Sachin Sant <sachinp@in.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

arch/s390/kernel/time.c

@@ -334,7 +334,7 @@ int get_sync_clock(unsigned long long *clock)
 	sw0 = atomic_read(sw_ptr);
 	*clock = get_clock();
 	sw1 = atomic_read(sw_ptr);
-	put_cpu_var(clock_sync_sync);
+	put_cpu_var(clock_sync_word);
 	if (sw0 == sw1 && (sw0 & 0x80000000U))
 		/* Success: time is in sync. */
 		return 0;
@@ -384,7 +384,7 @@ static inline int check_sync_clock(void)
 
 	sw_ptr = &get_cpu_var(clock_sync_word);
 	rc = (atomic_read(sw_ptr) & 0x80000000U) != 0;
-	put_cpu_var(clock_sync_sync);
+	put_cpu_var(clock_sync_word);
 	return rc;
 }