staging: rtl8723bs: remove function pointer xmit_thread_handler

Remove function pointer xmit_thread_handler and use
rtl8723bs_xmit_buf_handler directly to reduce code complexity.

Signed-off-by: Michael Straube <straube.linux@gmail.com>
Link: https://lore.kernel.org/r/20250715182814.212708-9-straube.linux@gmail.com


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>