[S390] Fix sparse warnings.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
diff --git a/arch/s390/kernel/time.c b/arch/s390/kernel/time.c
index f7fe9bc..74e6178 100644
--- a/arch/s390/kernel/time.c
+++ b/arch/s390/kernel/time.c
@@ -379,7 +379,7 @@
                                 -xtime.tv_sec, -xtime.tv_nsec);
 
 	/* request the clock comparator external interrupt */
-        if (register_early_external_interrupt(0x1004, 0,
+	if (register_early_external_interrupt(0x1004, NULL,
 					      &ext_int_info_cc) != 0)
                 panic("Couldn't request external interrupt 0x1004");