scripts/qmp-shell: move get_prompt() to prompt property

Small tidying; treat "prompt" like an immutable property instead of
function/method/routine.

Signed-off-by: John Snow <jsnow@redhat.com>
Message-id: 20210607200649.1840382-21-jsnow@redhat.com
Signed-off-by: John Snow <jsnow@redhat.com>

scripts/qmp/qmp-shell

@@ -292,10 +292,11 @@ class QMPShell(qmp.QEMUMonitorProtocol):
         version = self._greeting['QMP']['version']['qemu']
         print("Connected to QEMU {major}.{minor}.{micro}\n".format(**version))
 
-    def get_prompt(self):
+    @property
+    def prompt(self):
         if self._transmode:
-            return "TRANS> "
-        return "(QEMU) "
+            return 'TRANS> '
+        return '(QEMU) '
 
     def read_exec_command(self, prompt):
         """
@@ -435,7 +436,7 @@ def main():
         die(f"Couldn't connect to {args.qmp_server}: {err!s}")
 
     qemu.show_banner()
-    while qemu.read_exec_command(qemu.get_prompt()):
+    while qemu.read_exec_command(qemu.prompt):
         pass
     qemu.close()