Fix seccomp sandbox for gcc44

sandbox/linux/seccomp/debug.cc

Index: sandbox/linux/seccomp/debug.cc
diff --git a/sandbox/linux/seccomp/debug.cc b/sandbox/linux/seccomp/debug.cc
index b4f30a4fc96a2fa379aa70eb00270d327632d4ba..467b460fc857fb304e494a1ded1d88f09ae24174 100644
--- a/sandbox/linux/seccomp/debug.cc
+++ b/sandbox/linux/seccomp/debug.cc
@@ -148,7 +148,7 @@ void Debug::syscall(int sysnum, const char* msg, int call) {
     }
     char unnamed[40] = "Unnamed syscall #";
     if (!sysname) {
-      itoa(strrchr(sysname = unnamed, '\000'), sysnum);
+      itoa(const_cast<char*>(strrchr(sysname = unnamed, '\000')), sysnum);
     }
     #if defined(__NR_socketcall) || defined(__NR_ipc)
     char extra[40];