momery leak:recv and send on one connection

[humboldt-xie]

ngx_tcp_lua_socket_tcp_receive
==29006== 355,213,312 bytes in 86,722 blocks are possibly lost in loss record 145 of
==29006== at 0x4A0610C: malloc (vg_replace_malloc.c:195)
==29006== by 0x42C745: ngx_alloc (ngx_alloc.c:22)
==29006== by 0x41636B: ngx_palloc_large (ngx_palloc.c:223)
==29006== by 0x416476: ngx_palloc (ngx_palloc.c:142)
==29006== by 0x417EC1: ngx_create_temp_buf (ngx_buf.c:22)
==29006== by 0x49F8E9: ngx_tcp_lua_chains_get_free_buf (ngx_tcp_lua_util.c:623)
==29006== by 0x4A518A: ngx_tcp_lua_socket_tcp_receive (ngx_tcp_lua_socket.c:1150)
==29006== by 0x4C27A02: lj_BC_FUNCC (in /usr/local/nginx/luajit1/lib/libluajit-5.1.so.2.0.0)
==29006== by 0x49FB1F: ngx_tcp_lua_run_thread (ngx_tcp_lua_util.c:386)
==29006== by 0x49FCC5: ngx_tcp_lua_wev_handler (ngx_tcp_lua_util.c:517)
==29006== by 0x4A0BBF: ngx_tcp_lua_socket_handle_success (ngx_tcp_lua_socket.c:2009)
==29006== by 0x4A487D: ngx_tcp_lua_socket_read (ngx_tcp_lua_socket.c:1395)

[humboldt-xie]

ngx_tcp_lua_req_socket call great then 2 times