ACPICA: Fix a typo in a function header, no functional change

Reported by Colin King.
Signed-off-by: NColin Ian King <colin.king@canonical.com>
Signed-off-by: NBob Moore <robert.moore@intel.com>
Signed-off-by: NLv Zheng <lv.zheng@intel.com>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

drivers/acpi/acpica/evevent.c

@@ -258,7 +258,7 @@ u32 acpi_ev_fixed_event_detect(void)
  * DESCRIPTION: Clears the status bit for the requested event, calls the
  *              handler that previously registered for the event.
  *              NOTE: If there is no handler for the event, the event is
- *              disabled to prevent futher interrupts.
+ *              disabled to prevent further interrupts.
  *
  ******************************************************************************/