ssa.c: Fix smdb_dump directory in case of PRDB calculation failure

The smdb_dump directory name is changed from 'smdb_dump_dir/epoch'
to 'smdb_dump_dir.epoch', since it might cause an error when
calling 'mkdir()' and smdb_dump_dir doesn't exist.

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