ssa_db_helper.c: eliminate using 'rm' command for directory remove

Signed-off-by: Ilya Nelkenbaum <ilyan@mellanox.com>
Signed-off-by: Hal Rosenstock <hal@mellanox.com>
tests/loadsave: output directory handling was moved to ssa_db_save()

Signed-off-by: Ilya Nelkenbaum <ilyan@mellanox.com>
Signed-off-by: Hal Rosenstock <hal@mellanox.com>