iio: accel: fxls8962af: fix potential use of uninitialized symbol

Fix this warning from kernel test robot:
smatch warnings:
drivers/iio/accel/fxls8962af-core.c:640
fxls8962af_i2c_raw_read_errata3() error: uninitialized symbol 'ret'.
Reported-by: kernel test robot <lkp@intel.com>
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Sean Nyekjaer <sean@geanix.com>
Fixes: af959b7b ("iio: accel: fxls8962af: fix errata bug E3 - I2C burst reads")
Link: https://lore.kernel.org/r/20210709071727.2453536-1-sean@geanix.comSigned-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

drivers/iio/accel/fxls8962af-core.c

@@ -637,7 +637,7 @@ static int fxls8962af_i2c_raw_read_errata3(struct fxls8962af_data *data,
 			return ret;
 	}
 
-	return ret;
+	return 0;
 }
 
 static int fxls8962af_fifo_transfer(struct fxls8962af_data *data,