Revert "ktime: Simplify ktime_compare implementation"

Thierry bisected boot failures to this simplification commit.

Reverts: 3f1d4720 ("ktime: Simplify ktime_compare implementation")
Reported-by: Thierry Reding <thierry.reding@gmail.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Mariusz Skamra <mariuszx.skamra@intel.com>

include/linux/ktime.h

@@ -108,7 +108,11 @@ static inline ktime_t timeval_to_ktime(struct timeval tv)
  */
 static inline int ktime_compare(const ktime_t cmp1, const ktime_t cmp2)
 {
-	return ktime_sub(cmp1, cmp2);
+	if (cmp1 < cmp2)
+		return -1;
+	if (cmp1 > cmp2)
+		return 1;
+	return 0;
 }
 
 /**