staging: r8188eu: remove a buffer from rtw_writeN()

Remove the unnecessary buffer "u8 buf[VENDOR_CMD_MAX_DATA_LEN]" and
pass directly "data" to usbctrl_vendorreq().

Co-developed-by: Pavel Skripkin <paskripkin@gmail.com>
Signed-off-by: Pavel Skripkin <paskripkin@gmail.com>
Signed-off-by: Fabio M. De Francesco <fmdefrancesco@gmail.com>
Link: https://lore.kernel.org/r/20210924122705.3781-10-fmdefrancesco@gmail.com


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