init: Fix documentation about return values of void functions

Fixes T203

Signed-off-by: Jakub Jelen <jjelen@redhat.com>
Reviewed-by: Andreas Schneider <asn@cryptomilk.org>

src/init.c

@@ -106,7 +106,6 @@ _ret:
  *
  * This functions is automatically called when the library is loaded.
  *
- * @returns             0 on success, -1 if an error occured.
  */
 void libssh_constructor(void)
 {
@@ -188,8 +187,6 @@ _ret:
  *
  * This function is automatically called when the library is unloaded.
  *
- * @returns             SSH_OK on success, SSH_ERROR if an error occurred.
- *
  */
 void libssh_destructor(void)
 {