Fixed reference leak in error branch of _bufferedreader_read_all(). The variable…

Fixed reference leak in error branch of _bufferedreader_read_all(). The variable data can contain a bytes object but it wasn't cleaned up when PyList_New() failed. CID 715364

Modules/_io/bufferedio.c

@@ -1499,8 +1499,10 @@ _bufferedreader_read_all(buffered *self)
     }
 
     chunks = PyList_New(0);
-    if (chunks == NULL)
+    if (chunks == NULL) {
+        Py_XDECREF(data);
         return NULL;
+    }
 
     while (1) {
         if (data) {