plugin/ssa_smdb.c: change spaces in SMDB table names to '_'

This change is done for verification purposes.
Pointed out by Lenny.

Signed-off-by: Ilya Nelkenbaum <ilyan@mellanox.com>
Signed-off-by: Hal Rosenstock <hal@mellanox.com>
ssa_db_helper.c: change spaces to '_' in DATASET_DEF_FORMAT

Pointed out by Lenny.

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