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/common/autoboot.c b/common/autoboot.c
index 6251c68..b8861d5 100644
--- a/common/autoboot.c
+++ b/common/autoboot.c
@@ -69,7 +69,7 @@
  * before starting to enter the password.
  *
  * @etime: Timeout value ticks (stop when get_ticks() reachs this)
- * @return 0 if autoboot should continue, 1 if it should stop
+ * Return: 0 if autoboot should continue, 1 if it should stop
  */
 static int passwd_abort_crypt(uint64_t etime)
 {
@@ -143,7 +143,7 @@
  * This checks for the user entering a SHA256 hash within a given time.
  *
  * @etime: Timeout value ticks (stop when get_ticks() reachs this)
- * @return 0 if autoboot should continue, 1 if it should stop
+ * Return: 0 if autoboot should continue, 1 if it should stop
  */
 static int passwd_abort_sha256(uint64_t etime)
 {
@@ -219,7 +219,7 @@
  * This checks for the user entering a string within a given time.
  *
  * @etime: Timeout value ticks (stop when get_ticks() reachs this)
- * @return 0 if autoboot should continue, 1 if it should stop
+ * Return: 0 if autoboot should continue, 1 if it should stop
  */
 static int passwd_abort_key(uint64_t etime)
 {
@@ -315,7 +315,7 @@
  * sha256-fallback has been enabled via the config setting
  * `AUTOBOOT_SHA256_FALLBACK`.
  *
- * @return `false` if we must not fall-back, `true` if plain sha256 should be tried
+ * Return: `false` if we must not fall-back, `true` if plain sha256 should be tried
  */
 static bool fallback_to_sha256(void)
 {