It looks like Zach Brown's patch pr_debug-check-pr_debug-arguments
worked as inteded. That is, it doesn't "allow completely incorrect code
to build." :).

The arm build fails with the following message:
  CC      arch/arm/vfp/vfpsingle.o
  arch/arm/vfp/vfpsingle.c: In function `__vfp_single_normaliseround':
  arch/arm/vfp/vfpsingle.c:201: error: `func' undeclared (first use in
  this function)
  arch/arm/vfp/vfpsingle.c:201: error: (Each undeclared identifier is
  reported only once
  arch/arm/vfp/vfpsingle.c:201: error: for each function it appears in.)
  make[1]: *** [arch/arm/vfp/vfpsingle.o] Error 1
  make: *** [arch/arm/vfp] Error 2

The following patch fixes the issue by using func only when DEBUG is
defined.
Signed-off-by: Frederik Deweerdt <frederik.deweerdt@gmail.com>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: Zach Brown <zach.brown@oracle.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>