gru: fixes to grudump utility

Minor fixes to the SGI GRU grudump facility:
	- fix address where user data is written
	- add gru number to data passed to user
	- indicate if context is locked

Signed-off-by: Jack Steiner <steiner@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>