drivers/rtc/rtc-ab3100.c: add missing platform_set_drvdata() in ab3100_rtc_probe()

Otherwise, calling platform_get_drvdata() in ab3100_rtc_remove() returns
NULL.

Signed-off-by: Axel Lin <axel.lin@gmail.com>
Acked-by:Wan ZongShun <mcuos.com@gmail.com>
Acked-by: Linus Walleij <linus.walleij@stericsson.com>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

drivers/rtc/rtc-ab3100.c

@@ -235,6 +235,7 @@ static int __init ab3100_rtc_probe(struct platform_device *pdev)
 		err = PTR_ERR(rtc);
 		return err;
 	}
+	platform_set_drvdata(pdev, rtc);
 
 	return 0;
 }
@@ -244,6 +245,7 @@ static int __exit ab3100_rtc_remove(struct platform_device *pdev)
 	struct rtc_device *rtc = platform_get_drvdata(pdev);
 
 	rtc_device_unregister(rtc);
+	platform_set_drvdata(pdev, NULL);
 	return 0;
 }