Correct buffer unpinning logic in a PMNS traversal error path
Correct buffer unpinning logic in a PMNS traversal error path

This triggers an assertion failure in pminfo.  Redhat bugzilla
bug #847314, reported by Florian Weimer of the Redhat Security
team.

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