Fix a wrong format for triggerId.

Without this fix, sometimes it causes crash on 32bit environment.

   testActionManager::test_execCommandActionWithWrongPath:
 #0  0xb770d424 in __kernel_vsyscall ()
 #1  0xb766389b in waitpid () from /lib/i386-linux-gnu/libpthread.so.0
 #2  0xb720288d in g_on_error_stack_trace ()
 #3  0xb768ec54 in collect_backtrace () at cut-crash-backtrace.c:160
 #4  i_will_be_back_handler (signum=11) at cut-crash-backtrace.c:186
 #5  <signal handler called>
 #6  0xb74ea6a5 in vfprintf () from /lib/i386-linux-gnu/libc.so.6
 #7  0xb75a6238 in __vsnprintf_chk () from /lib/i386-linux-gnu/libc.so.6
 #8  0xb6a922e1 in vsnprintf (__ap=0xbfb2f670 "\340\260\333\b\275\036",
 #9  mlpl::StringUtils::vsprintf (
 #10 0xb6a91b92 in mlpl::Logger::log (level=mlpl::MLPL_LOG_BUG, fileName=0x0,
 #11 0xb6ea7084 in ActionManager::postProcSpawnFailure (actionDef=...,
 #12 0xb6ea73a4 in ActionManager::spawn (actionDef=..., eventInfo=...,