Fix a small memory leak.
Fix a small memory leak.

ycaihua/tcpcopy,horryq/tcpcopy,wfxiang08/tcpcopy,horryq/tcpcopy,sshling/tcpcopy,eliteYang/tcpcopy,u20024804/tcpcopy,daodaoliang/tcpcopy,ycaihua/tcpcopy,left2right/tcpcopy,caosiyang/tcpcopy,eliteYang/tcpcopy,wfxiang08/tcpcopy,caosiyang/tcpcopy,u20024804/tcpcopy,liviusATnetskope/second,daodaoliang/tcpcopy,sshling/tcpcopy,liviusATnetskope/second,left2right/tcpcopy