staging: r8188eu: clean up symbols in usbctrl_vendorreq()

Clean up symbol names in usbctrl_vendorreq():

	pdata => data;
	pio_priv => io_priv;
	pintfhdl => intf.

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/20210924122705.3781-2-fmdefrancesco@gmail.com


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