staging: lustre: embed kr_data into kkuc_reg

staging: lustre: embed kr_data into kkuc_reg

In struct kkuc_reg, the "kr_data" is difficult to be freed
outside of libcfs, then it's better to change it to be
inline data instead of the data pointer.

Signed-off-by: Hongchao Zhang <hongchao.zhang@intel.com>
Intel-bug-id: https://jira.hpdd.intel.com/browse/LU-6485
Reviewed-on: http://review.whamcloud.com/14638
Reviewed-by: John L. Hammond <john.hammond@intel.com>
Reviewed-by: James Simmons <uja.ornl@yahoo.com>
Reviewed-by: frank zago <fzago@cray.com>
Reviewed-by: Robert Read <robert.read@intel.com>
Reviewed-by: Henri Doreau <henri.doreau@cea.fr>
Reviewed-by: Oleg Drokin <oleg.drokin@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>