MEDIUM: stream-int: unconditionally call si_chk_rcv() in update and notify

MEDIUM: stream-int: unconditionally call si_chk_rcv() in update and notify

For a long time, stream_int_update() and stream_int_notify() used to only
conditionally call si_chk_rcv() based on state change detection. This
detection is not reliable and quite complex. With the new blocked flags
that si_chk_rcv() checks, it's much more reliable to always call the
function to take into account recent changes,and let it decide if it needs
to wake something up or not.

This also removes the calls to si_chk_rcv() that were performed in
si_update_both() since these ones are systematically performed in
stream_int_update() after updating the Rx flags.