drivers/rtc/rtc-test.c: avoid calling platform_device_put() twice

In case of error, test_init() needs to call platform_device_del() instead
of platform_device_unregister().  Otherwise, we may call
platform_device_put() twice.

dpatch engine is used to auto generate this patch.
(https://github.com/weiyj/dpatch

)

[akpm@linux-foundation.org: improve label naming]
Signed-off-by: Wei Yongjun <yongjun_wei@trendmicro.com.cn>
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>