char: qemu_chr_write_log() use qemu_write_full()

logfd is blocking, so we don't need to care about EAGAIN.
Let's simply use qemu_write_full().

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-ID: <20260201173633.413934-2-vsementsov@yandex-team.ru>

chardev/char.c

@@ -82,29 +82,17 @@ void qemu_chr_be_event(Chardev *s, QEMUChrEvent event)
     CHARDEV_GET_CLASS(s)->chr_be_event(s, event);
 }
 
-/* Not reporting errors from writing to logfile, as logs are
- * defined to be "best effort" only */
 static void qemu_chr_write_log(Chardev *s, const uint8_t *buf, size_t len)
 {
-    size_t done = 0;
-    ssize_t ret;
-
     if (s->logfd < 0) {
         return;
     }
 
-    while (done < len) {
-    retry:
-        ret = write(s->logfd, buf + done, len - done);
-        if (ret == -1 && errno == EAGAIN) {
-            g_usleep(100);
-            goto retry;
-        }
-
-        if (ret <= 0) {
-            return;
-        }
-        done += ret;
+    if (qemu_write_full(s->logfd, buf, len) < len) {
+        /*
+         * qemu_write_full() is defined with G_GNUC_WARN_UNUSED_RESULT,
+         * but logging is best‑effort, we do ignore errors.
+         */
     }
 }