The function handle_txrpt_ccx_88e() is only used in usb_ops_linux.c.
Make it static and remove the now empty file rtl8188e_xmit.c.

Tested-by: Philipp Hortmann <philipp.g.hortmann@gmail.com> # Edimax N150
Signed-off-by: Michael Straube <straube.linux@gmail.com>
Link: https://lore.kernel.org/r/20220804105532.7532-2-straube.linux@gmail.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>