Don't finish the handshake twice

We finish the handshake when we move into the TLS_ST_OK state. At various
points we were also unnecessarily finishing it when we were reading/writing
the Finished message. It's much simpler just to do it in TLS_ST_OK, so
remove the other calls.

Reviewed-by: Viktor Dukhovni <viktor@openssl.org>

ssl/statem/statem_srvr.c

@@ -876,12 +876,6 @@ WORK_STATE ossl_statem_server_post_process_message(SSL *s, WORK_STATE wst)
 #endif
         return WORK_FINISHED_CONTINUE;
 
-
-    case TLS_ST_SR_FINISHED:
-        if (s->hit)
-            return tls_finish_handshake(s, wst);
-        else
-            return WORK_FINISHED_STOP;
     default:
         break;
     }