alpha: Fix uninitialized value in read_persistent_clock.

Signed-off-by: Richard Henderson <[e-mail]>
Signed-off-by: Linus Torvalds <[e-mail]>

arch/alpha/kernel/time.c

···
 		year += 100;
 
 	ts->tv_sec = mktime(year, mon, day, hour, min, sec);
+	ts->tv_nsec = 0;
 }