sched/cpuacct: Add cpuacct_acount_field()

So we can remove open-coded cpuacct code in cputime.c.

Signed-off-by: Li Zefan <lizefan@huawei.com>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/51553692.9060008@huawei.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
diff --git a/kernel/sched/cpuacct.h b/kernel/sched/cpuacct.h
index 551acd7..bd0409b 100644
--- a/kernel/sched/cpuacct.h
+++ b/kernel/sched/cpuacct.h
@@ -43,6 +43,7 @@
 
 extern void cpuacct_init(void);
 extern void cpuacct_charge(struct task_struct *tsk, u64 cputime);
+extern void cpuacct_account_field(struct task_struct *p, int index, u64 val);
 
 #else
 
@@ -54,4 +55,9 @@
 {
 }
 
+static inline void
+cpuacct_account_field(struct task_struct *p, int index, u64 val)
+{
+}
+
 #endif