chardev: don't use alias names in parse_compat()

"parport" is considered "old" since commit 88a946d32d, when "parallel"
was added. Similarly for "tty" in commit d59044ef74.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>

chardev/char.c

@@ -450,12 +450,12 @@ QemuOpts *qemu_chr_parse_compat(const char *label, const char *filename)
     }
     if (strstart(filename, "/dev/parport", NULL) ||
         strstart(filename, "/dev/ppi", NULL)) {
-        qemu_opt_set(opts, "backend", "parport", &error_abort);
+        qemu_opt_set(opts, "backend", "parallel", &error_abort);
         qemu_opt_set(opts, "path", filename, &error_abort);
         return opts;
     }
     if (strstart(filename, "/dev/", NULL)) {
-        qemu_opt_set(opts, "backend", "tty", &error_abort);
+        qemu_opt_set(opts, "backend", "serial", &error_abort);
         qemu_opt_set(opts, "path", filename, &error_abort);
         return opts;
     }