hrtimers: fix docbook comments

hrtimer_start() and hrtimer_start_range_ns() handle relative and
absolute timers.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

kernel/hrtimer.c

@@ -946,7 +946,7 @@ remove_hrtimer(struct hrtimer *timer, struct hrtimer_clock_base *base)
 }
 
 /**
- * hrtimer_start_range_ns - (re)start an relative timer on the current CPU
+ * hrtimer_start_range_ns - (re)start an hrtimer on the current CPU
  * @timer:	the timer to be added
  * @tim:	expiry time
  * @delta_ns:	"slack" range for the timer
@@ -1022,7 +1022,7 @@ hrtimer_start_range_ns(struct hrtimer *timer, ktime_t tim, unsigned long delta_n
 EXPORT_SYMBOL_GPL(hrtimer_start_range_ns);
 
 /**
- * hrtimer_start - (re)start an relative timer on the current CPU
+ * hrtimer_start - (re)start an hrtimer on the current CPU
  * @timer:	the timer to be added
  * @tim:	expiry time
  * @mode:	expiry mode: absolute (HRTIMER_ABS) or relative (HRTIMER_REL)