ssa.c: Cosmetic change to remove trailing whitespace

Signed-off-by: Sasha Kotchubievsky <sashakot@mellanox.com>
Signed-off-by: Hal Rosenstock <hal@mellanox.com>
ssa.c: In ssa_downstream_close_ssa_conn, make sure connection parameter is valid

and not already closed (NULL)

Signed-off-by: Hal Rosenstock <hal@mellanox.com>
sa.c: Use pointers instead of pthread_t for access_thread and access_prdb_handler

 Static, global pointers are initialized by 0. It allows to check them
 in destroy and to join only if the thread was actually created.
ssa.c: Avoid blocking in case of uninitialized socket pair

 If ibssa application is exiting as result after
 ib device opening failure, the sock is uninitialized.
 IO operation on unitized socket could crash of block the
 application.
ssa.c: smdb ref. object may be NULL. Fix the crash.

 If ibssa application couldn't open ib devices and exits,
 smdb pointer is NULL.
ssa.c: Call ibv_close_device only if verbs pointer is not NULL.

 If ibssa application couldn't open ib devices and exits,
 verbs pointer is NULL.