acct: Use ktime_get_ts()

do_posix_clock_monotonic_gettime() is a leftover from the initial
posix timer implementation which maps to ktime_get_ts()

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: John Stultz <john.stultz@linaro.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20140611234606.764810535@linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

kernel/acct.c

@@ -484,7 +484,7 @@ static void do_acct_process(struct bsd_acct_struct *acct,
 	strlcpy(ac.ac_comm, current->comm, sizeof(ac.ac_comm));
 
 	/* calculate run_time in nsec*/
-	do_posix_clock_monotonic_gettime(&uptime);
+	ktime_get_ts(&uptime);
 	run_time = (u64)uptime.tv_sec*NSEC_PER_SEC + uptime.tv_nsec;
 	run_time -= (u64)current->group_leader->start_time.tv_sec * NSEC_PER_SEC
 		       + current->group_leader->start_time.tv_nsec;