Fix: remove logically dead code in send_channel_uid_to_ust

Fix: remove logically dead code in send_channel_uid_to_ust

Found by Coverity:

at_most: At condition ret < 0, the value of ret must be at most -1.
    cannot_set: At condition ret < 0, the value of ret cannot be equal
to any of {-1030, -32}.
    dead_error_condition: The condition ret < 0 must be true.
2825                        } else if (ret < 0) {
2826                                goto error_stream_unlock;
2827                        }
    CID 1323135 (#1 of 1): Logically dead code
(DEADCODE)dead_error_line: Execution cannot reach this statement: goto
error_stream_unlock;.

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>