fix: improve schema validation for bandit

In the course of some other refactoring in cvedb.py, we've got another
way to handle schema valiation such that bandit won't complain.

* fixes intel#3933
* closes intel#3965

Signed-off-by: Terri Oda <terri.oda@intel.com>

cve_bin_tool/cvedb.py

@@ -344,7 +344,7 @@ def latest_schema(
 
         self.LOGGER.debug("Check database is using latest schema")
         cursor = self.db_open_and_get_cursor()
-        schema_check = f"SELECT * FROM {table_name} WHERE 1=0"  # nosec
+        schema_check = self.EMPTY_SELECT_QUERIES[table_name]
         result = cursor.execute(schema_check)
         schema_latest = False