NAME
	UnLock -- Unlock a directory or file

    SYNOPSIS
	UnLock( lock )
		D1

	void UnLock( BPTR)

    FUNCTION
	The filing system lock (obtained from  Lock(),  DupLock(), or
	 CreateDir()) is removed and deallocated.

    INPUTS
	lock - BCPL pointer to a lock

    NOTE
	passing zero to UnLock() is harmless

    SEE ALSO
	 Lock(),  DupLock(),  ParentOfFH(),  DupLockFromFH()