s390/appldata_os: fix cpu array size calculation

The cpu array size calculation uses the NR_CPUS config option, which
was recently increased from 64 to 256. With a value of 256, the cpu
array will no longer fit into one APPLDATA record and loading the
appldata_os module fails with the following error:
could not insert 'appldata_os': Cannot allocate memory

Use num_possible_cpus() instead of NR_CPUS. For z/VM, this will still
result in a value of 64. This is not true for LPAR, but the appldata
feature is not available for LPAR.

Signed-off-by: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

arch/s390/appldata/appldata_os.c

@@ -171,7 +171,7 @@ static int __init appldata_os_init(void)
 	int rc, max_size;
 
 	max_size = sizeof(struct appldata_os_data) +
-		   (NR_CPUS * sizeof(struct appldata_os_per_cpu));
+		   (num_possible_cpus() * sizeof(struct appldata_os_per_cpu));
 	if (max_size > APPLDATA_MAX_REC_SIZE) {
 		pr_err("Maximum OS record size %i exceeds the maximum "
 		       "record size %i\n", max_size, APPLDATA_MAX_REC_SIZE);