fix doc errors

Fix various errors in the documentation that make doxygen complain.

Signed-off-by: Clemens Ladisch <clemens@ladisch.de>

src/control/control.c

@@ -211,7 +211,7 @@ int snd_ctl_poll_descriptors_revents(snd_ctl_t *ctl, struct pollfd *pfds, unsign
 }
 
 /**
- * \brief Ask to be informed about events (poll, #snd_ctl_async, #snd_ctl_read)
+ * \brief Ask to be informed about events (poll, #snd_async_add_ctl_handler, #snd_ctl_read)
  * \param ctl CTL handle
  * \param subscribe 0 = unsubscribe, 1 = subscribe
  * \return 0 on success otherwise a negative error code

src/control/control_ext.c

@@ -586,7 +586,7 @@ total number of control elements.  The elem_list returns the control element ID
 of the corresponding element offset (the offset is from 0 to elem_count - 1).
 The id field is initialized to all zero in prior to elem_list callback.  The callback
 has to fill the necessary field (typically iface, name and index) in return via the
-standard control API functions like #snd_ctl_elem_id_set_ifarce,
+standard control API functions like #snd_ctl_elem_id_set_interface,
 #snd_ctl_elem_id_set_name and #snd_ctl_elem_id_set_index, etc.  The callbacks should
 return 0 if successful, or a negative error code.
 

src/control/tlv.c

@@ -405,7 +405,6 @@ static int get_tlv_info(snd_ctl_t *ctl, const snd_ctl_elem_id_t *id,
  * \brief Get the dB min/max values on the given control element
  * \param ctl the control handler
  * \param id the element id
- * \param volume the raw volume value to convert
  * \param min the pointer to store the minimum dB value (in 0.01dB unit)
  * \param max the pointer to store the maximum dB value (in 0.01dB unit)
  * \return 0 if successful, or a negative error code