include/asm-ppc/rwsem.h has '#ifdef RWSEM_DEBUG' but RWSEM_DEBUG is always
defined (as 0) in include/linux/rwsem.h.  The #ifdef's should be #if's. 
This also brings the ppc usage in line with the the other architectures.
Signed-off-by: Mark A. Greer <mgreer@mvista.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>