354 - check only one pmlogger found to kill off
354 - check only one pmlogger found to kill off

Due to another failure in libpcp-gui, there where some old pmloggers
running, and the logic in 354 assumes only one pmlogger is launched,
so check this assumption.

ryandoyle/pcp_original,tjanez/pcp,mbaldessari/pcp,adfernandes/pcp,mbaldessari/pcp,prasincs/pcp,ryandoyle/pcp_original,tjanez/pcp,wuliming/pcp,adfernandes/pcp,adfernandes/pcp,ryandoyle/pcp_original,ryandoyle/pcp_original,mbaldessari/pcp,adfernandes/pcp,wuliming/pcp,ryandoyle/pcp_original,andyvand/cygpcpfans,prasincs/pcp,edwardt/pcp,andyvand/cygpcpfans,edwardt/pcp,andyvand/cygpcpfans,edwardt/pcp,tjanez/pcp,prasincs/pcp,wuliming/pcp,aeg-aeg/pcpfans,andyvand/cygpcpfans,wuliming/pcp,tjanez/pcp,adfernandes/pcp,tjanez/pcp,aeg-aeg/pcpfans,ryandoyle/pcp_original,andyvand/cygpcpfans,edwardt/pcp,aeg-aeg/pcpfans,edwardt/pcp,aeg-aeg/pcpfans,wuliming/pcp,tjanez/pcp,tjanez/pcp,ryandoyle/pcp_original,adfernandes/pcp,prasincs/pcp,andyvand/cygpcpfans,andyvand/cygpcpfans,edwardt/pcp,aeg-aeg/pcpfans,prasincs/pcp,andyvand/cygpcpfans,wuliming/pcp,wuliming/pcp,aeg-aeg/pcpfans,ryandoyle/pcp_original,prasincs/pcp,mbaldessari/pcp,aeg-aeg/pcpfans,wuliming/pcp,prasincs/pcp,mbaldessari/pcp,tjanez/pcp,prasincs/pcp,edwardt/pcp,aeg-aeg/pcpfans,mbaldessari/pcp,edwardt/pcp,adfernandes/pcp,adfernandes/pcp