Fix format

src/query/exist_query.rs

@@ -22,7 +22,7 @@ impl ExistsQuery {
     /// Creates a new `ExistQuery` from the given field.
     ///
     /// This query matches all documents with at least one non-null value in the specified field.
-    /// This constructor never fails, but executing the search with this query will return an 
+    /// This constructor never fails, but executing the search with this query will return an
     /// error if the specified field doesn't exists or is not a fast field.
     pub fn new_exists_query(field: String) -> ExistsQuery {
         ExistsQuery { field_name: field }