Description of problem:
Client info doesn't vanish after client disconnect when using vnc display

Version-Release number of selected component (if applicable):
qemu-kvm-rhev-2.6.0-11.el7.x86_64

How reproducible:
100%

Steps to Reproduce:
1.Use vnc with cmd: # /usr/libexec/qemu-kvm -vnc :0 -monitor stdio -qmp tcp:localhost:4444,server,nowait

2.Connect vnc display from local:
# vncviewer 127.0.0.1:5900 -Shared &
And query vnc client info from hmp:
{ "execute": "query-vnc" }


3.Establish another connection to vnc display from local:
# vncviewer 127.0.0.1:5900 &
Client from step 2 is disconnected and query vnc client info again from hmp:
{ "execute": "query-vnc" }

Actual results:
After step 3, both vnc clients info can be queried from hmp:
{ "execute": "query-vnc" }
{"return": {"enabled": true, "auth": "none", "family": "ipv4", "clients": [{"family": "ipv4", "service": "57104", "host": "10.66.10.63", "websocket": false}, {"family": "ipv4", "service": "57100", "host": "10.66.10.63", "websocket": false}], "service": "5900", "host": "0.0.0.0"}}



Expected results:
After step 3, only client info from step 3 exists and can be queried from hmp, this should like:
{ "execute": "query-vnc" }
{"return": {"enabled": true, "auth": "none", "family": "ipv4", "clients": [{"family": "ipv4", "service": "57104", "host": "10.66.10.63", "websocket": false}], "service": "5900", "host": "0.0.0.0"}}

Additional info:
Try same steps on qemu-kvm-rhev-2.3.0-31.el7_2.16.x86_64, no such issue happen.
After step2, query from hmp:
{ "execute": "query-vnc" }
{"return": {"enabled": true, "auth": "none", "family": "ipv4", "clients": [{"family": "ipv4", "service": "37606", "host": "127.0.0.1", "websocket": false}], "service": "5900", "host": "0.0.0.0"}}

After step 3, query from hmp:
{ "execute": "query-vnc" }
{"return": {"enabled": true, "auth": "none", "family": "ipv4", "clients": [{"family": "ipv4", "service": "37608", "host": "127.0.0.1", "websocket": false}], "service": "5900", "host": "0.0.0.0"}}