[PATCH] convert that currently tests _NSIG directly to use valid_signal()

Convert most of the current code that uses _NSIG directly to instead use
valid_signal().  This avoids gcc -W warnings and off-by-one errors.

Signed-off-by: Jesper Juhl <juhl-lkml@dif.dk>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/ipc/mqueue.c b/ipc/mqueue.c
index 33f7152..0acf245 100644
--- a/ipc/mqueue.c
+++ b/ipc/mqueue.c
@@ -23,6 +23,7 @@
 #include <linux/skbuff.h>
 #include <linux/netlink.h>
 #include <linux/syscalls.h>
+#include <linux/signal.h>
 #include <net/sock.h>
 #include "util.h"
 
@@ -976,8 +977,7 @@
 			     notification.sigev_notify != SIGEV_THREAD))
 			return -EINVAL;
 		if (notification.sigev_notify == SIGEV_SIGNAL &&
-			(notification.sigev_signo < 0 ||
-			 notification.sigev_signo > _NSIG)) {
+			!valid_signal(notification.sigev_signo)) {
 			return -EINVAL;
 		}
 		if (notification.sigev_notify == SIGEV_THREAD) {