staging: lustre: lnet: make sure lnet data not greater than LIBCFS_IOC_DATA_MAX

Fail to compile if largest LNet user land data structures passed
to kernel are larger than LIBCFS_IOC_DATA_MAX
Signed-off-by: Liang Zhen <liang.zhen@intel.com>
Intel-bug-id: https://jira.hpdd.intel.com/browse/LU-5435
Reviewed-on: http://review.whamcloud.com/11313Reviewed-by: Bobi Jam <bobijam@gmail.com>
Reviewed-by: Johann Lombardi <johann.lombardi@intel.com>
Reviewed-by: Oleg Drokin <oleg.drokin@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/lustre/lnet/lnet/api-ni.c

@@ -1864,6 +1864,10 @@ LNetCtl(unsigned int cmd, void *arg)
 	int rc;
 	unsigned long secs_passed;
 
+	BUILD_BUG_ON(LIBCFS_IOC_DATA_MAX <
+		     sizeof(struct lnet_ioctl_net_config) +
+		     sizeof(struct lnet_ioctl_config_data));
+
 	switch (cmd) {
 	case IOC_LIBCFS_GET_NI:
 		rc = LNetGetId(data->ioc_count, &id);