timekeeping: Avoid duplicate leap state update

timekeeping: Avoid duplicate leap state update

do_adjtimex() invokes tk_update_leap_state() unconditionally even when a
previous invocation of timekeeping_update() already did that update.

Put it into the else path which is invoked when timekeeping_update() is not
called.

Signed-off-by: Anna-Maria Behnsen <anna-maria@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: John Stultz <jstultz@google.com>
Link: https://lore.kernel.org/all/20241009-devel-anna-maria-b4-timers-ptp-timekeeping-v2-3-554456a44a15@linutronix.de