libertas: remove set but not used variable 'int_type'

Fixes gcc '-Wunused-but-set-variable' warning:

drivers/net/wireless/marvell/libertas/if_spi.c: In function 'if_spi_h2c':
drivers/net/wireless/marvell/libertas/if_spi.c:799:6: warning:
 variable 'int_type' set but not used [-Wunused-but-set-variable]

It never used since introduction in
commit d2b21f19 ("libertas: if_spi, driver for libertas GSPI devices")
Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Tested-by: Lubomir Rintel <lkundrak@v3.sk>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>

drivers/net/wireless/marvell/libertas/if_spi.c

@@ -796,15 +796,13 @@ static void if_spi_h2c(struct if_spi_card *card,
 {
 	struct lbs_private *priv = card->priv;
 	int err = 0;
-	u16 int_type, port_reg;
+	u16 port_reg;
 
 	switch (type) {
 	case MVMS_DAT:
-		int_type = IF_SPI_CIC_TX_DOWNLOAD_OVER;
 		port_reg = IF_SPI_DATA_RDWRPORT_REG;
 		break;
 	case MVMS_CMD:
-		int_type = IF_SPI_CIC_CMD_DOWNLOAD_OVER;
 		port_reg = IF_SPI_CMD_RDWRPORT_REG;
 		break;
 	default: