ui/console: remove chardev frontend connected test

The test if the chardev frontend is connected in
kbd_put_keysym_console() is redundant, because the call
to qemu_chr_be_can_write() in kbd_send_chars() tests
the connected condition again.

Remove the redundant test whether the chardev frontend
is connected.

Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Signed-off-by: Volker Rümelin <vr_qemu@t-online.de>
Message-Id: <20210916192239.18742-3-vr_qemu@t-online.de>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>