scripts/qmp: Use Python 2.6 "except E as ..." syntax

PEP 8 calls for it, because it's forward compatible with Python 3.
Supported since Python 2.6, which we require (commit fec2103).

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Acked-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-Id: <1450425164-24969-3-git-send-email-armbru@redhat.com>

scripts/qmp/qmp.py

@@ -92,7 +92,7 @@ class QEMUMonitorProtocol:
         self.__sock.setblocking(0)
         try:
             self.__json_read()
-        except socket.error, err:
+        except socket.error as err:
             if err[0] == errno.EAGAIN:
                 # No data available
                 pass
@@ -150,7 +150,7 @@ class QEMUMonitorProtocol:
         """
         try:
             self.__sock.sendall(json.dumps(qmp_cmd))
-        except socket.error, err:
+        except socket.error as err:
             if err[0] == errno.EPIPE:
                 return
             raise socket.error(err)