Fix a possible NULL reference that would be triggered by invalid input in /etc/crontab.
Fix a possible NULL reference that would be triggered
by invalid input in /etc/crontab.

MFC after:	2 days

jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase