tools: iio: Add ARRAY_SIZE macro

Calculation of the length of an array can be done with the ARRAY_SIZE
macro to make code more abstract and remove the associated
checkpatch.pl warning.

Signed-off-by: Cristina Opriceana <cristina.opriceana@gmail.com>
Acked-by: Hartmut Knaack <knaack.h@gmx.de>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
diff --git a/tools/iio/iio_utils.h b/tools/iio/iio_utils.h
index 0866101..f30a109 100644
--- a/tools/iio/iio_utils.h
+++ b/tools/iio/iio_utils.h
@@ -18,6 +18,8 @@
 #define FORMAT_SCAN_ELEMENTS_DIR "%s/scan_elements"
 #define FORMAT_TYPE_FILE "%s_type"
 
+#define ARRAY_SIZE(arr) (sizeof(arr) / sizeof(arr[0]))
+
 extern const char *iio_dir;
 
 /**