LU-7623 gss: Update upcall structure with user attributes

LU-7623 gss: Update upcall structure with user attributes

This helps to better track userspace pointers and keeps sparse happy.

Also fix gss_do_ctx_init_rpc definition and sync up the forward
declaration

Signed-off-by: Oleg Drokin <oleg.drokin@intel.com>
Change-Id: I10c1a7dd58531886bf8cfa8c684ea6fba321c511
Reviewed-on: http://review.whamcloud.com/17790
Tested-by: Jenkins
Tested-by: Maloo <hpdd-maloo@intel.com>
Reviewed-by: James Simmons <uja.ornl@yahoo.com>
Reviewed-by: John L. Hammond <john.hammond@intel.com>
Reviewed-by: Jeremy Filizetti <jeremy.filizetti@gmail.com>
Reviewed-by: Sebastien Buisson <sbuisson@ddn.com>
Reviewed-by: Frank Zago <fzago@cray.com>