fixed another spot of -Werror=unused-but-set-variable warning issued by gcc 4.6.0.
fixed another spot of -Werror=unused-but-set-variable warning issued by gcc 4.6.0.

yeahdongcn/SEnginx,yeahdongcn/SEnginx,yeahdongcn/SEnginx,yeahdongcn/SEnginx,yeahdongcn/SEnginx,yeahdongcn/SEnginx,yeahdongcn/SEnginx