staging:iio:ade7753/ade7754/ade7759: Use spi_w8r16be() instead of spi_w8r16()

Using spi_w8r16be() will do the conversion of the result from big endian to
native endian in the helper function. This makes the code a bit smaller and also
keeps sparse happy. Fixes the following sparse warnings:

drivers/staging/iio/meter/ade7753.c:97:29: warning: incorrect type in argument 1 (different base types)
drivers/staging/iio/meter/ade7753.c:97:29: expected restricted __be16 const [usertype] *p
drivers/staging/iio/meter/ade7753.c:97:29: got unsigned short [usertype] *val

drivers/staging/iio/meter/ade7754.c:97:29: warning: incorrect type in argument 1 (different base types)
drivers/staging/iio/meter/ade7754.c:97:29: expected restricted __be16 const [usertype] *p
drivers/staging/iio/meter/ade7754.c:97:29: got unsigned short [usertype] *val

drivers/staging/iio/meter/ade7759.c:97:29: warning: incorrect type in argument 1 (different base types)
drivers/staging/iio/meter/ade7759.c:97:29: expected restricted __be16 const [usertype] *p
drivers/staging/iio/meter/ade7759.c:97:29: got unsigned short [usertype] *val

Signed-off-by: Lars-Peter Clausen <[e-mail]>
Acked-by: Jonathan Cameron <[e-mail]>
Signed-off-by: Mark Brown <[e-mail]>

drivers/staging/iio/meter/ade7753.c

···
 	struct ade7753_state *st = iio_priv(indio_dev);
 	ssize_t ret;
 
-	ret = spi_w8r16(st->us, ADE7753_READ_REG(reg_address));
+	ret = spi_w8r16be(st->us, ADE7753_READ_REG(reg_address));
 	if (ret < 0) {
 		dev_err(&st->us->dev, "problem when reading 16 bit register 0x%02X",
 			reg_address);
···
 	}
 
 	*val = ret;
-	*val = be16_to_cpup(val);
 
 	return 0;
 }

drivers/staging/iio/meter/ade7754.c

···
 	struct ade7754_state *st = iio_priv(indio_dev);
 	int ret;
 
-	ret = spi_w8r16(st->us, ADE7754_READ_REG(reg_address));
+	ret = spi_w8r16be(st->us, ADE7754_READ_REG(reg_address));
 	if (ret < 0) {
 		dev_err(&st->us->dev, "problem when reading 16 bit register 0x%02X",
 			reg_address);
···
 	}
 
 	*val = ret;
-	*val = be16_to_cpup(val);
 
 	return 0;
 }

drivers/staging/iio/meter/ade7759.c

···
 	struct ade7759_state *st = iio_priv(indio_dev);
 	int ret;
 
-	ret = spi_w8r16(st->us, ADE7759_READ_REG(reg_address));
+	ret = spi_w8r16be(st->us, ADE7759_READ_REG(reg_address));
 	if (ret < 0) {
 		dev_err(&st->us->dev, "problem when reading 16 bit register 0x%02X",
 			reg_address);
···
 	}
 
 	*val = ret;
-	*val = be16_to_cpup(val);
 
 	return 0;
 }