s390/zcrypt: fix possible memory leak in ap_module_init()

ap_configuration is malloced in ap_module_init() and should be freed
before leaving from the error handling cases, otherwise it may cause
memory leak.

Signed-off-by: Wei Yongjun <weiyj.lk@gmail.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>