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: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>