Fix function types in doxygen docs

Signed-off-by: Jakub Hrozek <jakub.hrozek@posteo.se>
Reviewed-by: Andreas Schneider <asn@cryptomilk.org>
diff --git a/include/cmocka.h b/include/cmocka.h
index 35100d0..797fbe2 100644
--- a/include/cmocka.h
+++ b/include/cmocka.h
@@ -1533,7 +1533,7 @@
  *      return 0;
  * }
  *
- * static void teardown(void **state) {
+ * static int teardown(void **state) {
  *      free(*state);
  *
  *      return 0;
@@ -1601,7 +1601,7 @@
  *      return 0;
  * }
  *
- * static void teardown(void **state) {
+ * static int teardown(void **state) {
  *      free(*state);
  *
  *      return 0;