off-by-one bug in truss

[Nicolas Thery]

truss cores dump while handling a syscall that is one past the last
syscall known to it.  This happens typically after adding a new
syscall to the kernel and before rebuilding truss.

The following patch fixes this.

Index: dfly/src/usr.bin/truss/i386-fbsd.c
===================================================================
--- dfly.orig/src/usr.bin/truss/i386-fbsd.c	2003-11-04 16:34:41.000000000 +0100
+++ dfly/src/usr.bin/truss/i386-fbsd.c	2007-12-20 18:30:30.000000000 +0100
@@ -157,7 +157,7 @@

   fsc.number = syscall;
   fsc.name =
-    (syscall < 0 || syscall > nsyscalls) ? NULL : syscallnames[syscall];
+    (syscall < 0 || syscall >= nsyscalls) ? NULL : syscallnames[syscall];
   if (!fsc.name) {
     fprintf(outfile, "-- UNKNOWN SYSCALL %d --\n", syscall);
   }
Index: dfly/src/usr.bin/truss/i386-linux.c
===================================================================
--- dfly.orig/src/usr.bin/truss/i386-linux.c	2003-11-04 16:34:41.000000000 +0100
+++ dfly/src/usr.bin/truss/i386-linux.c	2007-12-20 18:31:19.000000000 +0100
@@ -116,7 +116,7 @@

   lsc.number = syscall;
   lsc.name =
-    (syscall < 0 || syscall > nsyscalls) ? NULL : linux_syscallnames[syscall];
+    (syscall < 0 || syscall >= nsyscalls) ? NULL : linux_syscallnames[syscall];
   if (!lsc.name) {
     fprintf (outfile, "-- UNKNOWN SYSCALL %d\n", syscall);
   }