cdea756569
On success, the number of bytes written should be returned. Previously `buf.len()` was always returned. The function `send_slice` > ... returns the amount of octets actually enqueued, which is limited > by the amount of free space in the transmit buffer; down to zero. "down to zero" is okay as that is checked by `can_send`. Signed-off-by: Anhad Singh <andypython@protonmail.com>