ssl/t1_enc: Fix kTLS RX offload path

During counting of the unprocessed records, return code is treated in a
wrong way. This forces kTLS RX path to be skipped in case of presence
of unprocessed records.

CLA: trivial

Reviewed-by: Tomas Mraz <tomas@openssl.org>
Reviewed-by: Matt Caswell <matt@openssl.org>
Reviewed-by: Paul Dale <pauli@openssl.org>
(Merged from #17492)

(cherry picked from commit d73a7a3)

ssl/t1_enc.c

@@ -122,7 +122,7 @@ static int count_unprocessed_records(SSL *s)
             return -1;
 
         /* Read until next record */
-        if (PACKET_get_length_prefixed_2(&pkt, &subpkt))
+        if (!PACKET_get_length_prefixed_2(&pkt, &subpkt))
             return -1;
 
         count += 1;