Be sure that check_buf() updates the event record pointer after a realloc.
Be sure that check_buf() updates the event record pointer after a realloc.

Without this change, if realloc() moved the buffer around (instead of
just lengthening it), the current event record pointer will point to
the old address, not the new.  This can happen if an event record is
added, then two event parameter are added (the 2nd causing a
realloc()).

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