Revert "python/qmp/protocol: add open_with_socket()"

This reverts commit a3cfea92e2030926e00a2519d299384ea648e36e.

(It's being rolled back in favor of a different API, which brings the
in-tree and out-of-tree versions of qemu.qmp back in sync.)

Signed-off-by: John Snow <jsnow@redhat.com>
Message-id: 20230517163406.2593480-6-jsnow@redhat.com
Signed-off-by: John Snow <jsnow@redhat.com>

python/qemu/qmp/protocol.py

@@ -297,19 +297,6 @@ async def start_server_and_accept(
         await self.accept()
         assert self.runstate == Runstate.RUNNING
 
-    @upper_half
-    @require(Runstate.IDLE)
-    async def open_with_socket(self, sock: socket.socket) -> None:
-        """
-        Start connection with given socket.
-
-        :param sock: A socket.
-
-        :raise StateError: When the `Runstate` is not `IDLE`.
-        """
-        self._reader, self._writer = await asyncio.open_connection(sock=sock)
-        self._set_state(Runstate.CONNECTING)
-
     @upper_half
     @require(Runstate.IDLE)
     async def start_server(self, address: SocketAddrT,
@@ -357,12 +344,11 @@ async def accept(self) -> None:
             protocol-level failure occurs while establishing a new
             session, the wrapped error may also be an `QMPError`.
         """
-        if not self._reader:
-            if self._accepted is None:
-                raise QMPError("Cannot call accept() before start_server().")
-            await self._session_guard(
-                self._do_accept(),
-                'Failed to establish connection')
+        if self._accepted is None:
+            raise QMPError("Cannot call accept() before start_server().")
+        await self._session_guard(
+            self._do_accept(),
+            'Failed to establish connection')
         await self._session_guard(
             self._establish_session(),
             'Failed to establish session')