RWSEM_DEBUG used to be a printk based 'tracing' facility, probably used for
very early prototypes of the rwsem code.  Remove it.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>