tests: Print read bytes to debug failures

Signed-off-by: Jakub Jelen <jjelen@redhat.com>
Reviewed-by: Pavol Žáčik <pzacik@redhat.com>
Reviewed-by: Andreas Schneider <asn@cryptomilk.org>

tests/client/torture_auth_agent_forwarding.c

@@ -205,6 +205,7 @@ static void torture_auth_agent_forwarding(void **state)
 
         if (nbytes > 0) {
             buffer[nbytes] = 0;
+            ssh_log_hexdump("Read bytes:", (unsigned char *)buffer, nbytes);
 
             /* Process the command output to check for three key conditions:
              * 1. If SSH_AUTH_SOCK is properly set (meaning agent forwarding