vtime: Explicitly account pending user time on process tick

All vtime implementations just flush the user time on process
tick. Consolidate that in generic code by calling a user time
accounting helper. This avoids an indirect call in ia64 and
prepare to also consolidate vtime context switch code.

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Reviewed-by: Steven Rostedt <rostedt@goodmis.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
diff --git a/include/linux/vtime.h b/include/linux/vtime.h
index 5ad13c3..ae30ab5 100644
--- a/include/linux/vtime.h
+++ b/include/linux/vtime.h
@@ -8,6 +8,7 @@
 extern void vtime_account_system(struct task_struct *tsk);
 extern void vtime_account_system_irqsafe(struct task_struct *tsk);
 extern void vtime_account_idle(struct task_struct *tsk);
+extern void vtime_account_user(struct task_struct *tsk);
 extern void vtime_account(struct task_struct *tsk);
 #else
 static inline void vtime_task_switch(struct task_struct *prev) { }