vgroup_id	IN:	Vgroup identifier returned by Vattach
	vgroup_class	OUT:	Class name of the vgroup

	Purpose	Retrieves the class name of a vgroup.
	Return value	Returns SUCCEED (or 0) if successful and FAIL (or -1) otherwise.
	Description	Vgetclass retrieves the class name of the vgroup identified by the parameter vgroup_id in the buffer vgroup_class.
		The maximum length of the name is defined by VGNAMELENMAX (or 64).

	FORTRAN	integer function vfgcls(vgroup_id, vgroup_class)
		integer vgroup_id
		character*(*) vgroup_class