qa/200: avoid race on pmcd socket
qa/200: avoid race on pmcd socket

When restarting pmcd, replace "start" by "stop; sleep 2; start".
This seems to be enough to ensure the pmcd request socket is
completely shutdown before pmcd starts again, avoiding the
occasional "socket busy" failure.

aeg-aeg/pcpfans,aeg-aeg/pcpfans,wuliming/pcp,aeg-aeg/pcpfans,adfernandes/pcp,adfernandes/pcp,adfernandes/pcp,wuliming/pcp,aeg-aeg/pcpfans,adfernandes/pcp,wuliming/pcp,aeg-aeg/pcpfans,aeg-aeg/pcpfans,adfernandes/pcp,wuliming/pcp,aeg-aeg/pcpfans,aeg-aeg/pcpfans,adfernandes/pcp,wuliming/pcp,adfernandes/pcp,wuliming/pcp,adfernandes/pcp,wuliming/pcp,wuliming/pcp