staging/lustre/md: fix lu_ucred.c boilerplate

In preparing Ie3a3cd99 (LU-1330 obdclass: splits server-side object
stack from client) the lu_ucred infrastructure was put in its own
file.  Fixup the boilerplate of this file to give the proper path,
short description, and authors.

Intel-bug-id: https://jira.hpdd.intel.com/browse/LU-1330
Lustre-change: http://review.whamcloud.com/5910
Signed-off-by: John L. Hammond <john.hammond@intel.com>
Reviewed-by: Fan Yong <fan.yong@intel.com>
Reviewed-by: Vitaly Fertman <vitaly_fertman@xyratex.com>
Reviewed-by: Oleg Drokin <oleg.drokin@intel.com>
Signed-off-by: Peng Tao <tao.peng@emc.com>
Signed-off-by: Andreas Dilger <andreas.dilger@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>