dialect/sql: change boolean operators wrapping (#678)

The reason is to parentheses only when it's necessary.

dialect/sql/schema/sqlite.go

@@ -36,7 +36,10 @@ func (d *SQLite) init(ctx context.Context, tx dialect.Tx) error {
 func (d *SQLite) tableExist(ctx context.Context, tx dialect.Tx, name string) (bool, error) {
 	query, args := sql.Select().Count().
 		From(sql.Table("sqlite_master")).
-		Where(sql.EQ("type", "table").And().EQ("name", name)).
+		Where(sql.And(
+			sql.EQ("type", "table"),
+			sql.EQ("name", name),
+		)).
 		Query()
 	return exist(ctx, tx, query, args...)
 }