Fix typos from signal_32/64.h merge

Fallout from commit 33185c50 ("x86:
merge signal_32/64.h")

Thanks to Dick Streefland who provided an useful testcase on
http://lkml.org/lkml/2008/3/17/205 (only applicable to 2.6.24.x), that
helped a lot as a deterministic way to bisect an issue that leaded to
this fix.
Signed-off-by: NHerton Ronaldo Krzesinski <herton@mandriva.com.br>
Signed-off-by: NLuiz Fernando N. Capitulino <lcapitulino@mandriva.com.br>
Cc: Roland McGrath <roland@redhat.com>
Cc: <stable@kernel.org>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

include/asm-x86/signal.h

@@ -181,12 +181,12 @@ typedef struct sigaltstack {
 #ifdef __KERNEL__
 #include <asm/sigcontext.h>
 
-#ifdef __386__
+#ifdef __i386__
 
 #define __HAVE_ARCH_SIG_BITOPS
 
 #define sigaddset(set,sig)		    \
-	(__builtin_constantp(sig)	    \
+	(__builtin_constant_p(sig)	    \
 	 ? __const_sigaddset((set), (sig))  \
 	 : __gen_sigaddset((set), (sig)))