s390/zcrypt: fix memory leak with ap configuration data

The ap_query_configuration function allocates the ap_config_info
structure, but there is no code to free the structure.
Allocate the structure in the module_init function and free it
again in module_exit.

While we are at it simplify a few functions in regard to the
ap configuration data.
Reviewed-by: Ingo Tuchscherer <ingo.tuchscherer@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

drivers/s390/crypto/ap_bus.h

@@ -76,11 +76,8 @@ struct ap_queue_status {
 } __packed;
 
 
-#define AP_MAX_BITS 31
 static inline int ap_test_bit(unsigned int *ptr, unsigned int nr)
 {
-	if (nr > AP_MAX_BITS)
-		return 0;
 	return (*ptr & (0x80000000u >> nr)) != 0;
 }