HV: Fix the missing list_head initializaiton

Signed-off-by: Zide Chen <zide.chen@intel.com>
Acked-by: Anthony Xu <anthony.xu@intel.com>

include/arch/x86/timer.h

@@ -61,6 +61,7 @@ static inline void initialize_timer(struct timer *timer,
 		timer->fire_tsc = fire_tsc;
 		timer->mode = mode;
 		timer->period_in_cycle = period_in_cycle;
+		INIT_LIST_HEAD(&timer->node);
 	}
 }