src/libpcp/src/pdu.c: add fault injection check for __pmGetPDU()
src/libpcp/src/pdu.c: add fault injection check for __pmGetPDU()

If the class PM_FAULT_TIMEOUT has been armed, return immediately
with PM_ERR_TIMEOUT.

Note this generates no code for the regular libpcp, it is only
enabled in libpcp_fault.

adfernandes/pcp,adfernandes/pcp,adfernandes/pcp,adfernandes/pcp,adfernandes/pcp,adfernandes/pcp,adfernandes/pcp,adfernandes/pcp