ntp: Convert functions with only two states to bool

ntp: Convert functions with only two states to bool

is_error_status() and ntp_synced() return whether a state is set or
not. Both functions use unsigned int for it even if it would be a perfect
job for a bool.

Use bool instead of unsigned int. And while at it, move ntp_synced()
function to the place where it is used.

No functional change.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
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/20240911-devel-anna-maria-b4-timers-ptp-ntp-v1-5-2d52f4e13476@linutronix.de