Fix a number of Coverity findings

- 1458048: Use-after-free in the SQLite logger
- 1457823: Missing a break statement in script-opt reduction
- 1453966: Dead code in CompHash
- 1445417: Unintialized variable in StaticHash64
- 1437716: Unintialized variables in FileInfo in scan.l

src/script_opt/Reduce.cc

@@ -959,6 +959,7 @@ TraversalCode CSE_ValidityChecker::PreExpr(const Expr* e)
 			return TC_ABORTALL;
 			}
 		}
+		break;
 
 	case EXPR_APPEND_TO:
 		// This doesn't directly change any identifiers, but does