ui: remove useless typecasts

ui: remove useless typecasts

Commit 8f9abdf586 ("chardev: src buffer const for write functions")
changed the type of the second parameter of qemu_chr_be_write()
from uint8_t * to const uint8_t *. Remove the now useless type
casts from qemu_chr_be_write() function calls in ui/console.c and
ui/gtk.c.

Cc: qemu-trivial@nongnu.org
Signed-off-by: Volker Rümelin <vr_qemu@t-online.de>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Claudio Fontana <cfontana@suse.de>
Message-Id: <20221022141204.29358-1-vr_qemu@t-online.de>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>