fanout.Close: nil checking moved inside, no need to check outside
fanout.Close: nil checking moved inside, no need to check outside

Signed-off-by: Wang Xu <0e9dfdf30d71e7ded2bba4a3dc006039c4b00f3d@gmail.com>

laijs/runv,bergwolf/runv,wrouesnel/runv,feiskyer/runv,gao-feng/runv,feiskyer/runv,jinfenw/runv,gao-feng/runv,hyperhq/runv,gnawux/runv,hyperhq/runv,hyperhq/runv,gnawux/runv,gnawux/runv,laijs/runv,wrouesnel/runv,laijs/runv,jinfenw/runv,jinfenw/runv,gao-feng/runv,YaoZengzeng/runv,bergwolf/runv,bergwolf/runv,YaoZengzeng/runv