staging: wilc1000: remove spi_trx of wilc_wlan_io_func_t

This patch removes spi_trx of wilc_wlan_io_func_t which is not used anymore.
Delete it's related codes also.
Signed-off-by: Glen Lee <glen.lee@atmel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/wilc1000/linux_wlan.c

@@ -898,7 +898,6 @@ void linux_to_wlan(wilc_wlan_inp_t *nwi, struct wilc *nic)
 	nwi->io_func.io_type = HIF_SPI;
 	nwi->io_func.io_init = linux_spi_init;
 	nwi->io_func.io_deinit = linux_spi_deinit;
-	nwi->io_func.u.spi.spi_trx = linux_spi_write_read;
 	nwi->io_func.u.spi.spi_max_speed = linux_spi_set_max_speed;
 #endif
 }

drivers/staging/wilc1000/wilc_wlan_if.h

@@ -79,7 +79,6 @@ typedef struct {
 	union {
 		struct {
 			int (*spi_max_speed)(void);
-			int (*spi_trx)(u8 *, u8 *, u32);
 		} spi;
 	} u;
 } wilc_wlan_io_func_t;