Revert "x86/tsc: Prepare warp test for TSC adjustment"

This reverts commit 76d3b851.

The returned value for check_tsc_warp() is useless now, remove it.
Signed-off-by: NJiufei Xue <jiufei.xue@linux.alibaba.com>
Reviewed-by: NJoseph Qi <joseph.qi@linux.alibaba.com>

arch/x86/kernel/tsc_sync.c

@@ -222,9 +222,9 @@ static int random_warps;
  * TSC-warp measurement loop running on both CPUs.  This is not called
  * if there is no TSC.
  */
-static cycles_t check_tsc_warp(unsigned int timeout)
+static void check_tsc_warp(unsigned int timeout)
 {
-	cycles_t start, now, prev, end, cur_max_warp = 0;
+	cycles_t start, now, prev, end;
 	int i, cur_warps = 0;
 
 	start = rdtsc_ordered();
@@ -265,7 +265,6 @@ static cycles_t check_tsc_warp(unsigned int timeout)
 		if (unlikely(prev > now)) {
 			arch_spin_lock(&sync_lock);
 			max_warp = max(max_warp, prev - now);
-			cur_max_warp = max_warp;
 			/*
 			 * Check whether this bounces back and forth. Only
 			 * one CPU should observe time going backwards.
@@ -280,7 +279,6 @@ static cycles_t check_tsc_warp(unsigned int timeout)
 	WARN(!(now-start),
 		"Warning: zero tsc calibration delta: %Ld [max: %Ld]\n",
 			now-start, end-start);
-	return cur_max_warp;
 }
 
 /*