staging: iio: if(__LITTLE_ENDIAN) -> #ifdef __LITTLE_ENDIAN

Unsuprisingly this symbol isn't defined on big endian systems.
Signed-off-by: Jonathan Cameron <jic23@cam.ac.uk>
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

drivers/staging/iio/industrialio-buffer.c

@@ -104,10 +104,11 @@ static ssize_t iio_show_fixed_type(struct device *dev,
 	u8 type = this_attr->c->scan_type.endianness;
 
 	if (type == IIO_CPU) {
-		if (__LITTLE_ENDIAN)
+#ifdef __LITTLE_ENDIAN
 		type = IIO_LE;
-		else
+#else
 		type = IIO_BE;
+#endif
 	}
 	return sprintf(buf, "%s:%c%d/%d>>%u\n",
 		       iio_endian_prefix[type],