kernel/auditsc.c: fix an off-by-one

This patch fixes an off-by-one in a BUG_ON() spotted by the Coverity
checker.

Signed-off-by: Adrian Bunk <bunk@stusta.de>
Cc: Amy Griffis <amy.griffis@hp.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

kernel/auditsc.c

@@ -2023,7 +2023,7 @@ int __audit_signal_info(int sig, struct task_struct *t)
 		axp->d.next = ctx->aux_pids;
 		ctx->aux_pids = (void *)axp;
 	}
-	BUG_ON(axp->pid_count > AUDIT_AUX_PIDS);
+	BUG_ON(axp->pid_count >= AUDIT_AUX_PIDS);
 
 	axp->target_pid[axp->pid_count] = t->tgid;
 	selinux_get_task_sid(t, &axp->target_sid[axp->pid_count]);