scripts/qmp-shell: use triple-double-quote docstring style

(2014 me had never written python before.)

Signed-off-by: John Snow <jsnow@redhat.com>
Message-id: 20210607200649.1840382-11-jsnow@redhat.com
Signed-off-by: John Snow <jsnow@redhat.com>

scripts/qmp/qmp-shell

@@ -94,9 +94,12 @@ class QMPShellError(Exception):
 
 
 class FuzzyJSON(ast.NodeTransformer):
-    '''This extension of ast.NodeTransformer filters literal "true/false/null"
+    """
+    This extension of ast.NodeTransformer filters literal "true/false/null"
     values in an AST and replaces them by proper "True/False/None" values that
-    Python can properly evaluate.'''
+    Python can properly evaluate.
+    """
+
     @classmethod
     def visit_Name(cls, node):
         if node.id == 'true':