firmware: Sigma: Skip header during CRC generation

The firmware header is not part of the CRC, so skip it. Otherwise the firmware
will be rejected due to non-matching CRCs.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Acked-by: Mike Frysinger <vapier@gentoo.org>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Cc: stable@kernel.org

drivers/firmware/sigma.c

@@ -130,7 +130,8 @@ int process_sigma_firmware(struct i2c_client *client, const char *name)
 	if (memcmp(ssfw_head->magic, SIGMA_MAGIC, ARRAY_SIZE(ssfw_head->magic)))
 		goto done;
 
-	crc = crc32(0, fw->data, fw->size);
+	crc = crc32(0, fw->data + sizeof(*ssfw_head),
+			fw->size - sizeof(*ssfw_head));
 	pr_debug("%s: crc=%x\n", __func__, crc);
 	if (crc != ssfw_head->crc)
 		goto done;