gcc noticed (when using -Wempty-body) that our use of
lock_cmos() and unlock_cmos() in
arch/x86/include/asm/mach_traps.h is potentially problematic :

  arch/x86/include/asm/mach_traps.h:32:15: warning: suggest braces around empty body in an ¡else¢ statement [-Wempty-body]
  arch/x86/include/asm/mach_traps.h:40:16: warning: suggest braces around empty body in an ¡else¢ statement [-Wempty-body]

Let's just use the standard 'do {} while (0)' solution. That
shuts up gcc and also prevents future problems if the macros
should end up being used in a similar situation elsewhere.
Signed-off-by: NJesper Juhl <jj@chaosbits.net>
Link: http://lkml.kernel.org/r/alpine.LNX.2.00.1112180103130.21784@swampdragon.chaosbits.netSigned-off-by: NIngo Molnar <mingo@elte.hu>