staging: iio: ad5933: fix order of cycle conditions

Correctly handle the settling time cycles value. The else branch is an
impossible condition, > 1022 in the else branch of > 511. Flipping the order.

Based on the Table 13 at the bottom of Page 25 of the Data Sheet:
http://www.analog.com/media/en/technical-documentation/data-sheets/AD5933.pdf

Signed-off-by: Luis de Bethencourt <luisbg@osg.samsung.com>
Reviewed-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

drivers/staging/iio/impedance-analyzer/ad5933.c

@@ -444,10 +444,10 @@ static ssize_t ad5933_store(struct device *dev,
 		st->settling_cycles = val;
 
 		/* 2x, 4x handling, see datasheet */
-		if (val > 511)
-			val = (val >> 1) | (1 << 9);
-		else if (val > 1022)
+		if (val > 1022)
 			val = (val >> 2) | (3 << 9);
+		else if (val > 511)
+			val = (val >> 1) | (1 << 9);
 
 		dat = cpu_to_be16(val);
 		ret = ad5933_i2c_write(st->client,