[MEDIUM] split stream_sock_write() into callback and core functions

stream_sock_write() has been split in two parts :
  - the poll callback, intented to be called when an I/O event has
    been detected
  - the write() core function, which ought to be usable from various
    other places, possibly not meant to wake the task up.

The code has also been slightly cleaned up in the process. It's more
readable now.
1 file changed