sched/cputime: Rename vtime_account_user() to vtime_flush()

CONFIG_VIRT_CPU_ACCOUNTING_NATIVE=y used to accumulate user time and
account it on ticks and context switches only through the
vtime_account_user() function.

Now this model has been generalized on the 3 archs for all kind of
cputime (system, irq, ...) and all the cputime flushing happens under
vtime_account_user().

So let's rename this function to better reflect its new role.

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Stanislaw Gruszka <sgruszka@redhat.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Wanpeng Li <wanpeng.li@hotmail.com>
Link: http://lkml.kernel.org/r/1483636310-6557-11-git-send-email-fweisbec@gmail.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>

arch/powerpc/kernel/time.c

@@ -382,15 +382,13 @@ void vtime_account_idle(struct task_struct *tsk)
 }
 
 /*
- * Transfer the user time accumulated in the paca
- * by the exception entry and exit code to the generic
- * process user time records.
+ * Account the whole cputime accumulated in the paca
  * Must be called with interrupts disabled.
  * Assumes that vtime_account_system/idle() has been called
  * recently (i.e. since the last entry from usermode) so that
  * get_paca()->user_time_scaled is up to date.
  */
-void vtime_account_user(struct task_struct *tsk)
+void vtime_flush(struct task_struct *tsk)
 {
 	struct cpu_accounting_data *acct = get_accounting(tsk);