Fix a bug that made PAM fail if /etc/pam.d/ existed but was empty.
Fix a bug that made PAM fail if /etc/pam.d/ existed but was empty.

Sponsored by:	DARPA, NAI Labs

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