drivers/rtc/rtc-pcf50633.c: fix use after free in pcf50633_rtc_probe()

"rtc" is freed and then dereferenced on the next line.  This patch fixes
that.

Signed-off-by: Dan Carpenter <error27@gmail.com>
Acked-by: Alessandro Zummo <a.zummo@towertech.it>
Cc: David Brownell <david-b@pacbell.net>
Cc: Paul Gortmaker <p_gortmaker@yahoo.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>