[MIPS] Oprofile: fix sparse warning.
    
Signed-off-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
diff --git a/arch/mips/oprofile/common.c b/arch/mips/oprofile/common.c
index 49ef8fd..f2b4862 100644
--- a/arch/mips/oprofile/common.c
+++ b/arch/mips/oprofile/common.c
@@ -27,7 +27,7 @@
 	model->reg_setup(ctr);
 
 	/* Configure the registers on all cpus.  */
-	on_each_cpu(model->cpu_setup, 0, 0, 1);
+	on_each_cpu(model->cpu_setup, NULL, 0, 1);
 
         return 0;
 }