`mux_cnt` struct member never goes negative or decrements,
so mux chardev can be !busy only when there are no
frontends attached. This patch fixes the always-true
check.

Fixes: a4afa548fc6d ("char: move front end handlers in CharBackend")
Signed-off-by: Roman Penyaev <r.peniaev@gmail.com>
Cc: "Marc-André Lureau" <marcandre.lureau@redhat.com>
Cc: qemu-devel@nongnu.org
---
 chardev/char.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/chardev/char.c b/chardev/char.c
index c0cc52824b48..f54dc3a86286 100644
--- a/chardev/char.c
+++ b/chardev/char.c
@@ -333,7 +333,7 @@ static bool qemu_chr_is_busy(Chardev *s)
 {
     if (CHARDEV_IS_MUX(s)) {
         MuxChardev *d = MUX_CHARDEV(s);
-        return d->mux_cnt >= 0;
+        return d->mux_cnt > 0;
     } else {
         return s->be != NULL;
     }
-- 
2.34.1