[PATCH] fix lockdep-design.txt

I was looking at lockdep-desing.txt and i guess i am confused with the
changes with respect to fd7bcea3. It
says

+   '.'  acquired while irqs enabled
+   '+'  acquired in irq context
+   '-'  acquired in process context with irqs disabled
+   '?'  read-acquired both with irqs enabled and in irq context
+

But the get_usage_chars() function does this for '-'
 if (class->usage_mask & LOCKF_ENABLED_HARDIRQS)
                        *c1 = '-';

So i guess what would be correct would be
'.'  acquired while irqs disabled
'+'  acquired in irq context
'-'  acquired with irqs enabled
'?' read acquired in irq context with irqs enabled.

Acked-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>