revert "rtc: recycle id when unloading a rtc driver"

Revert commit 2830a6d2.

We already perform the ida_simple_remove() in rtc_device_release(),
which is an appropriate place.  Commit 2830a6d2 ("rtc: recycle id when
unloading a rtc driver") caused the kernel to emit

	ida_remove called for id=0 which is not allocated.

warnings when rtc_device_release() tries to release an alread-released
ID.

Let's restore things to their previous state and then work out why
Vincent's kernel wasn't calling rtc_device_release() - presumably a bug
in a specific sub-driver.
Reported-by: NLothar Waßmann <LW@KARO-electronics.de>
Acked-by: NAlexander Holler <holler@ahsoftware.de>
Cc: Vincent Palatin <vpalatin@chromium.org>
Cc: <stable@vger.kernel.org>		[3.7.x]
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

drivers/rtc/class.c

@@ -244,7 +244,6 @@ void rtc_device_unregister(struct rtc_device *rtc)
 		rtc_proc_del_device(rtc);
 		device_unregister(&rtc->dev);
 		rtc->ops = NULL;
-		ida_simple_remove(&rtc_ida, rtc->id);
 		mutex_unlock(&rtc->ops_lock);
 		put_device(&rtc->dev);
 	}