Fix adding papi metrics
Fix adding papi metrics

*src/pmdas/papi/papi.c - currently when we add enlarge papi_info,
		       	 we increase the size with a realloc, and then
			 memset the contents to zero.  Normally this would
			 be fine, however the .position member variable
			 (which represents the position in the values[] array)
			 is valid when set to zero (normally a negative number
			 when not in use for that metric).  Check that the
			 papi_info element we're trying to add also has a
			 non-zero papi_event_code before adding.

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