LU-6142 socklnd: change UAPI typedefs to proper structure

LU-6142 socklnd: change UAPI typedefs to proper structure

The upstream kernel requires proper structures so
convert all the UAPI typedefs in socklnd.h.

Remove the inline function socklnd_init_msg.
Its only used by the kernel code and functions
are not allowed in UAPI headers.

Change-Id: I4120c5abc4dda456289146452ed61e0162062cea
Signed-off-by: James Simmons <uja.ornl@yahoo.com>
Reviewed-on: https://review.whamcloud.com/18506
Reviewed-by: Dmitry Eremin <dmitry.eremin@intel.com>
Tested-by: Jenkins
Tested-by: Maloo <hpdd-maloo@intel.com>
Reviewed-by: Doug Oucharek <doug.s.oucharek@intel.com>
Reviewed-by: John L. Hammond <john.hammond@intel.com>
Reviewed-by: Oleg Drokin <oleg.drokin@intel.com>