fix fragile test

Author: methane

driver_test.go

@@ -165,14 +165,14 @@ func runTests(t *testing.T, dsn string, tests ...func(dbt *DBTest)) {
 	for _, test := range tests {
 		t.Run("default", func(t *testing.T) {
 			dbt := &DBTest{t, db}
+			defer dbt.db.Exec("DROP TABLE IF EXISTS test")
 			test(dbt)
-			dbt.db.Exec("DROP TABLE IF EXISTS test")
 		})
 		if db2 != nil {
 			t.Run("interpolateParams", func(t *testing.T) {
 				dbt2 := &DBTest{t, db2}
+				defer dbt2.db.Exec("DROP TABLE IF EXISTS test")
 				test(dbt2)
-				dbt2.db.Exec("DROP TABLE IF EXISTS test")
 			})
 		}
 	}