LU-4423 lnet: Don't ignore error code for lst_group_info_ioctl

LU-4423 lnet: Don't ignore error code for lst_group_info_ioctl

Error stored in rc was never reported, so directly return it here.

Linux-commit : 2a96be0d46825689ac9b6078056e523ba96acec4

Change-Id: I0535d0a101c1142f035e6dfba240e95fc9040eb2
Signed-off-by: Cristina Moraru <cristina.moraru09@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: James Simmons <uja.ornl@yahoo.com>
Reviewed-on: http://review.whamcloud.com/18952
Tested-by: Jenkins
Tested-by: Maloo <hpdd-maloo@intel.com>
Reviewed-by: Doug Oucharek <doug.s.oucharek@intel.com>
Reviewed-by: Dmitry Eremin <dmitry.eremin@intel.com>
Reviewed-by: Frank Zago <fzago@cray.com>
Reviewed-by: Oleg Drokin <oleg.drokin@intel.com>