define struct workqueue_struct in C file

[Liu, Changcheng]

Hi all,
	I have one confusion about workqueue_struct:
	1) Why struct workqueue_struct is defined in C file instead of
	header file?
	   I'm trying to print "workqueue_struct:name" field in one external
	   build module. "workqueue_struct:name" can't be accessed directly.

	2) struct work_struct is defined in "workqueue.h", could struct
	workqueue_struct also be defined in it?

--Thanks
Changcheng