ssa_db.[c h]: Adding 'data_tbl_cnt' counter to 'ssa_db' structure

'data_tbl_cnt' counts the number of data tables
contained in 'ssa_db' structure.

Signed-off-by: Ilya Nelkenbaum <ilyan@mellanox.com>
Signed-off-by: Hal Rosenstock <hal@mellanox.com>
ssa_db.h: Cosmetic formatting change

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