Properly unlock mutex before returning. There was a slight mishap during last major locking cleanup.
Properly unlock mutex before returning. There was a slight mishap
during last major locking cleanup.

Reported by:	Thierry Herbelot <thierry@herbelot.com>
Approved by:	re (mux)

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