sctp: Fix typos and improve comments

Fix typos s/steam/stream/ and spell out Schedule/Unschedule in the
comments.

Compile-tested only.

Signed-off-by: Thorsten Blum <thorsten.blum@toblux.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Link: https://patch.msgid.link/20240704202558.62704-2-thorsten.blum@toblux.com


Signed-off-by: Paolo Abeni <pabeni@redhat.com>