iio: proximity: as3935: fix as3935_write

AS3935_WRITE_DATA macro bit is incorrect and the actual write
sequence is two leading zeros.

Cc: George McCollister <george.mccollister@gmail.com>
Signed-off-by: Matt Ranostay <matt.ranostay@konsulko.com>
Cc: <Stable@vger.kernel.org>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

drivers/iio/proximity/as3935.c

@@ -50,7 +50,6 @@
 #define AS3935_TUNE_CAP		0x08
 #define AS3935_CALIBRATE	0x3D
 
-#define AS3935_WRITE_DATA	BIT(15)
 #define AS3935_READ_DATA	BIT(14)
 #define AS3935_ADDRESS(x)	((x) << 8)
 
@@ -105,7 +104,7 @@ static int as3935_write(struct as3935_state *st,
 {
 	u8 *buf = st->buf;
 
-	buf[0] = (AS3935_WRITE_DATA | AS3935_ADDRESS(reg)) >> 8;
+	buf[0] = AS3935_ADDRESS(reg) >> 8;
 	buf[1] = val;
 
 	return spi_write(st->spi, buf, 2);