HID: hid-logitech-hidpp: Fix conformant kernel-doc header and demote abuses

Fixes the following W=1 kernel build warning(s):

 drivers/hid/hid-logitech-hidpp.c:275: warning: Function parameter or member 'hidpp' not described in 'hidpp_send_message_sync'
 drivers/hid/hid-logitech-hidpp.c:275: warning: Function parameter or member 'message' not described in 'hidpp_send_message_sync'
 drivers/hid/hid-logitech-hidpp.c:275: warning: Function parameter or member 'response' not described in 'hidpp_send_message_sync'
 drivers/hid/hid-logitech-hidpp.c:275: warning: expecting prototype for and something else(). Prototype was for hidpp_send_message_sync() instead
 drivers/hid/hid-logitech-hidpp.c:427: warning: wrong kernel-doc identifier on line:
 drivers/hid/hid-logitech-hidpp.c:470: warning: Function parameter or member 'input_dev' not described in 'hidpp_scroll_counter_handle_scroll'
 drivers/hid/hid-logitech-hidpp.c:1894: warning: Function parameter or member 'hidpp' not described in 'hidpp_touchpad_fw_items_set'
 drivers/hid/hid-logitech-hidpp.c:1894: warning: Function parameter or member 'feature_index' not described in 'hidpp_touchpad_fw_items_set'
 drivers/hid/hid-logitech-hidpp.c:1894: warning: Function parameter or member 'items' not described in 'hidpp_touchpad_fw_items_set'
 drivers/hid/hid-logitech-hidpp.c:1894: warning: expecting prototype for send a set state command to the device by reading the current items(). Prototype was for hidpp_touchpad_fw_items_set() instead

Cc: Jiri Kosina <jikos@kernel.org>
Cc: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Cc: Henrik Rydberg <rydberg@bitmath.org>
Cc: Lopez Casado <nlopezcasad@logitech.com>
Cc: linux-input@vger.kernel.org
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>

drivers/hid/hid-logitech-hidpp.c

@@ -261,7 +261,7 @@ static int __hidpp_send_report(struct hid_device *hdev,
 	return ret == fields_count ? 0 : -1;
 }
 
-/**
+/*
  * hidpp_send_message_sync() returns 0 in case of success, and something else
  * in case of a failure.
  * - If ' something else' is positive, that means that an error has been raised
@@ -423,7 +423,7 @@ static inline bool hidpp_report_is_connect_event(struct hidpp_device *hidpp,
 		(report->rap.sub_id == 0x41));
 }
 
-/**
+/*
  * hidpp_prefix_name() prefixes the current given name with "Logitech ".
  */
 static void hidpp_prefix_name(char **name, int name_length)
@@ -454,6 +454,7 @@ static void hidpp_prefix_name(char **name, int name_length)
  * hidpp_scroll_counter_handle_scroll() - Send high- and low-resolution scroll
  *                                        events given a high-resolution wheel
  *                                        movement.
+ * @input_dev: Pointer to the input device
  * @counter: a hid_scroll_counter struct describing the wheel.
  * @hi_res_value: the movement of the wheel, in the mouse's high-resolution
  *                units.
@@ -1884,7 +1885,7 @@ struct hidpp_touchpad_fw_items {
 	uint8_t persistent;
 };
 
-/**
+/*
  * send a set state command to the device by reading the current items->state
  * field. items is then filled with the current state.
  */