doc: replace @return by Return:

Sphinx expects Return: and not @return to indicate a return value.

find . -name '*.c' -exec \
sed -i 's/^\(\s\)\*\(\s*\)@return\(\s\)/\1*\2Return:\3/' {} \;

find . -name '*.h' -exec \
sed -i 's/^\(\s\)\*\(\s*\)@return\(\s\)/\1*\2Return:\3/' {} \;

Signed-off-by: Heinrich Schuchardt <heinrich.schuchardt@canonical.com>
diff --git a/tools/image-host.c b/tools/image-host.c
index a6b0a94..945571f 100644
--- a/tools/image-host.c
+++ b/tools/image-host.c
@@ -55,7 +55,7 @@
  * @noffset:	subnode offset
  * @data:	data to process
  * @size:	size of data in bytes
- * @return 0 if ok, -1 on error
+ * Return: 0 if ok, -1 on error
  */
 static int fit_image_process_hash(void *fit, const char *image_name,
 		int noffset, const void *data, size_t size)
@@ -209,7 +209,7 @@
  * @comment:	Comment to add to signature nodes
  * @require_keys: Mark all keys as 'required'
  * @engine_id:	Engine to use for signing
- * @return 0 if ok, -1 on error
+ * Return: 0 if ok, -1 on error
  */
 static int fit_image_process_sig(const char *keydir, const char *keyfile,
 		void *keydest, void *fit, const char *image_name,