cansequence: do_send(): fix errno check

"errno" hold the positive error value.

Link: https://github.com/linux-can/can-utils/issues/448
Reported-by:  Adien Akhmad <adien.akhmad@gmail.com>
Suggested-by: Oliver Hartkopp <socketcan@hartkopp.net>
Fixes: fb5903f226 ("[cansequece] added various improvements")
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

cansequence.c

@@ -223,7 +223,7 @@ static void do_send()
 				}
 
 				err = poll(fds, 1, 1000);
-				if (err == 0 || (err == -1 && errno != -EINTR)) {
+				if (err == 0 || (err == -1 && errno != EINTR)) {
 					perror("poll()");
 					exit(EXIT_FAILURE);
 				}