pcp: ensure temp file cleanup happend before calling exec
pcp: ensure temp file cleanup happend before calling exec

Long-standing buglet uncovered by recent refactoring.  Win!

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