staging: r8712u: remove unused struct 'zero_bulkout_context'

Remove struct zero_bulkout_context as it is unused.

Signed-off-by: Dr. David Alan Gilbert <[e-mail]>
Tested-by: Philipp Hortmann <[e-mail]> AW-NU120
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Greg Kroah-Hartman <[e-mail]>

drivers/staging/rtl8712/usb_ops_linux.c

···
 #define	RTL871X_VENQT_READ	0xc0
 #define	RTL871X_VENQT_WRITE	0x40
 
-struct zero_bulkout_context {
-	void *pbuf;
-	void *purb;
-	void *pirp;
-	void *padapter;
-};
-
 uint r8712_usb_init_intf_priv(struct intf_priv *pintfpriv)
 {
 	pintfpriv->piorw_urb = usb_alloc_urb(0, GFP_ATOMIC);