qa/1045: add more diagnostics to try and catch file clobbering
qa/1045: add more diagnostics to try and catch file clobbering

Still trying to understand how pconf/cpu/load_average sometimes
ends up as an empty file.

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