ftp(1) prints TLS and short read errors to stdout rather than stderr

ftp(1) prints some of its errors to stdout, which may lead to confusion when used in scripts like syspatch(8).

	$ ftp -Mo /dev/null https://expired.badssl.com; echo $?
	Trying 104.154.89.105...
	TLS handshake failure: certificate verification failed: certificate has expired
	1

	$ ftp -Mo /dev/null https://expired.badssl.com > /dev/null; echo $?
	1


	$ openssl req -keyout /tmp/localhost.key -newkey rsa -nodes -out \
		/tmp/localhost.crt -subj '/CN=localhost' -x509
	$ printf 'HTTP/1.1 200 OK\nContent-Length:4711\n\n17' | nc -clN -C \
		/tmp/localhost.crt -K /tmp/localhost.key localhost 4443

	$ ftp -Mo /dev/null -S dont https://localhost:4443; echo $?
	Trying 127.0.0.1...
	Requesting https://localhost:4443
	Read short file.
	1

	$ ftp -Mo /dev/null -S dont https://localhost:4443 > /dev/null; echo $?
	1

Discovered by trying to run syspatch(8) on a machine with a Bios clock well into 2027, which caused syspatch to run in an interactive shell but fetch nothing and print nothing due to a perceived expired certificate.

From what I can tell, the relevant code goes back to the original SSL support implementation back in 2006:

	https://cvsweb.openbsd.org/diff/src/usr.bin/ftp/fetch.c?rev=1.61&prev=1.60

The diff mirrors how errors are printed in the surrounding code. Feedback is welcome though as I am still rather new to OpenBSD hacking.

diff /usr/src
path + /usr/src
commit - 95a78e283c1363d0a2f44ed4baea4243f1abf975
blob - 453f6fd269851e8f4023e726128821ff2b4a15c3
file + usr.bin/ftp/fetch.c
--- usr.bin/ftp/fetch.c
+++ usr.bin/ftp/fetch.c
@@ -644,23 +644,22 @@ noslash:
 				errx(1, "Can't allocate memory for https host.");
 		}
 		if ((tls = tls_client()) == NULL) {
-			fprintf(ttyout, "failed to create SSL client\n");
+			warnx("failed to create SSL client");
 			goto cleanup_url_get;
 		}
 		if (tls_configure(tls, tls_config) != 0) {
-			fprintf(ttyout, "TLS configuration failure: %s\n",
-			    tls_error(tls));
+			warnx("TLS configuration failure: %s", tls_error(tls));
 			goto cleanup_url_get;
 		}
 		if (tls_connect_socket(tls, fd, sslhost) != 0) {
-			fprintf(ttyout, "TLS connect failure: %s\n", tls_error(tls));
+			warnx("TLS connect failure: %s", tls_error(tls));
 			goto cleanup_url_get;
 		}
 		do {
 			ret = tls_handshake(tls);
 		} while (ret == TLS_WANT_POLLIN || ret == TLS_WANT_POLLOUT);
 		if (ret != 0) {
-			fprintf(ttyout, "TLS handshake failure: %s\n", tls_error(tls));
+			warnx("TLS handshake failure: %s", tls_error(tls));
 			goto cleanup_url_get;
 		}
 		fin = funopen(tls, stdio_tls_read_wrapper,
@@ -1101,7 +1100,7 @@ noslash:
 #endif /* !SMALL */
 		filesize != -1 && len == 0 && bytes != filesize) {
 		if (verbose)
-			fputs("Read short file.\n", ttyout);
+			warnx("Read short file.");
 		goto cleanup_url_get;
 	}