Revert "qstring: add qstring_free()"

This reverts commit 164c374b75.

A free function for a reference-counted object is in bad taste.
Fortunately, this one is now also unused.  Drop it.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20201211171152.146877-7-armbru@redhat.com>

include/qapi/qmp/qstring.h

@@ -34,7 +34,6 @@ void qstring_append_int(QString *qstring, int64_t value);
 void qstring_append(QString *qstring, const char *str);
 void qstring_append_chr(QString *qstring, int c);
 bool qstring_is_equal(const QObject *x, const QObject *y);
-char *qstring_free(QString *qstring, bool return_str);
 void qstring_destroy_obj(QObject *obj);
 
 #endif /* QSTRING_H */

qobject/qstring.c

@@ -168,33 +168,16 @@ bool qstring_is_equal(const QObject *x, const QObject *y)
                    qobject_to(QString, y)->string);
 }
 
-/**
- * qstring_free(): Free the memory allocated by a QString object
- *
- * Return: if @return_str, return the underlying string, to be
- * g_free(), otherwise NULL is returned.
- */
-char *qstring_free(QString *qstring, bool return_str)
-{
-    char *rv = NULL;
-
-    if (return_str) {
-        rv = qstring->string;
-    } else {
-        g_free(qstring->string);
-    }
-
-    g_free(qstring);
-
-    return rv;
-}
-
 /**
  * qstring_destroy_obj(): Free all memory allocated by a QString
  * object
  */
 void qstring_destroy_obj(QObject *obj)
 {
+    QString *qs;
+
     assert(obj != NULL);
-    qstring_free(qobject_to(QString, obj), FALSE);
+    qs = qobject_to(QString, obj);
+    g_free(qs->string);
+    g_free(qs);
 }