Correction on InterProcessLock 

This correction enables opening a new file without causing all the AcquireLock blocking with AbandonedMutexException caused by incorrect state on ReleaseLock, namely m_mutexClosed.

The bug was found using InterProcessLockwith RollingFileAppender with date pattern on file name, at midnight the new file is opened and all logging becomes blocked at InterProcessLock.AcquireLock on m_mutex.WaitOne.