media: cxd2880-spi: Fix a null pointer dereference on error handling path

Currently the null pointer check on dvb_spi->vcc_supply is inverted and
this leads to only null values of the dvb_spi->vcc_supply being passed
to the call of regulator_disable causing null pointer dereferences.
Fix this by only calling regulator_disable if dvb_spi->vcc_supply is
not null.

Addresses-Coverity: ("Dereference after null check")

Fixes: dcb01458 ("media: cxd2880-spi: Fix an error handling path")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Sean Young <sean@mess.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>

drivers/media/spi/cxd2880-spi.c

@@ -618,7 +618,7 @@ cxd2880_spi_probe(struct spi_device *spi)
 fail_attach:
 	dvb_unregister_adapter(&dvb_spi->adapter);
 fail_adapter:
-	if (!dvb_spi->vcc_supply)
+	if (dvb_spi->vcc_supply)
 		regulator_disable(dvb_spi->vcc_supply);
 fail_regulator:
 	kfree(dvb_spi);