ptp: Fix clock_getres() implementation

The clock_getres() function must return the resolution in the timespec
argument and return 0 for success.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Acked-by: NJohn Stultz <john.stultz@linaro.org>
Cc: stable@kernel.org
Cc: Richard Cochran <richard.cochran@omicron.at>

drivers/ptp/ptp_clock.c

@@ -101,7 +101,9 @@ static s32 scaled_ppm_to_ppb(long ppm)
 
 static int ptp_clock_getres(struct posix_clock *pc, struct timespec *tp)
 {
-	return 1; /* always round timer functions to one nanosecond */
+	tp->tv_sec = 0;
+	tp->tv_nsec = 1;
+	return 0;
 }
 
 static int ptp_clock_settime(struct posix_clock *pc, const struct timespec *tp)