core.c: Reverse source and destination GID so from client perspective

Signed-off-by: Hal Rosenstock <hal@mellanox.com>
Signed-off-by: Ira Weiny <ira.weiny@intel.com>
core.c: In core_construct, handle ssa_open_devices failure

Signed-off-by: Hal Rosenstock <hal@mellanox.com>
Signed-off-by: Ira Weiny <ira.weiny@intel.com>
ssa.c: Save parent in ssa_svc structure

Also, change SSA service state from ORPHAN to HAVE_PARENT

Signed-off-by: Hal Rosenstock <hal@mellanox.com>
Acked-by: Sean Hefty <sean.hefty@intel.com>
Signed-off-by: Ira Weiny <ira.weiny@intel.com>