docs: Use ‘Returns:’ instead of the invalid ‘@returns’

This is based on the commit 59a24ab5a3 in GLib.

Signed-off-by: Philip Withnall <withnall@endlessm.com>
diff --git a/gvdb-reader.c b/gvdb-reader.c
index bc4de09..1ec6633 100644
--- a/gvdb-reader.c
+++ b/gvdb-reader.c
@@ -125,7 +125,6 @@
  * @bytes: the #GBytes with the data
  * @trusted: if the contents of @bytes are trusted
  * @error: %NULL, or a pointer to a %NULL #GError
- * @returns: a new #GvdbTable
  *
  * Creates a new #GvdbTable from the contents of @bytes.
  *
@@ -133,6 +132,8 @@
  *
  * You should call gvdb_table_free() on the return result when you no
  * longer require it.
+ *
+ * Returns: a new #GvdbTable
  **/
 GvdbTable *
 gvdb_table_new_from_bytes (GBytes    *bytes,
@@ -184,10 +185,11 @@
  * @filename: a filename
  * @trusted: if the contents of @bytes are trusted
  * @error: %NULL, or a pointer to a %NULL #GError
- * @returns: a new #GvdbTable
  *
  * Creates a new #GvdbTable using the #GMappedFile for @filename as the
  * #GBytes.
+ *
+ * Returns: a new #GvdbTable
  **/
 GvdbTable *
 gvdb_table_new (const gchar  *filename,
@@ -474,7 +476,6 @@
  * gvdb_table_list:
  * @file: a #GvdbTable
  * @key: a string
- * @returns: a %NULL-terminated string array
  *
  * List all of the keys that appear below @key.  The nesting of keys
  * within the hash file is defined by the program that created the hash
@@ -487,6 +488,8 @@
  *
  * You should call g_strfreev() on the return result when you no longer
  * require it.
+ *
+ * Returns: a %NULL-terminated string array
  **/
 gchar **
 gvdb_table_list (GvdbTable   *file,
@@ -537,12 +540,13 @@
  * gvdb_table_has_value:
  * @file: a #GvdbTable
  * @key: a string
- * @returns: %TRUE if @key is in the table
  *
  * Checks for a value named @key in @file.
  *
  * Note: this function does not consider non-value nodes (other hash
  * tables, for example).
+ *
+ * Returns: %TRUE if @key is in the table
  **/
 gboolean
 gvdb_table_has_value (GvdbTable    *file,
@@ -586,7 +590,6 @@
  * gvdb_table_get_value:
  * @file: a #GvdbTable
  * @key: a string
- * @returns: a #GVariant, or %NULL
  *
  * Looks up a value named @key in @file.
  *
@@ -596,6 +599,8 @@
  *
  * You should call g_variant_unref() on the return result when you no
  * longer require it.
+ *
+ * Returns: a #GVariant, or %NULL
  **/
 GVariant *
 gvdb_table_get_value (GvdbTable    *file,
@@ -625,12 +630,13 @@
  * gvdb_table_get_raw_value:
  * @table: a #GvdbTable
  * @key: a string
- * @returns: a #GVariant, or %NULL
  *
  * Looks up a value named @key in @file.
  *
  * This call is equivalent to gvdb_table_get_value() except that it
  * never byteswaps the value.
+ *
+ * Returns: a #GVariant, or %NULL
  **/
 GVariant *
 gvdb_table_get_raw_value (GvdbTable   *table,
@@ -648,7 +654,6 @@
  * gvdb_table_get_table:
  * @file: a #GvdbTable
  * @key: a string
- * @returns: a new #GvdbTable, or %NULL
  *
  * Looks up the hash table named @key in @file.
  *
@@ -662,6 +667,8 @@
  *
  * You should call gvdb_table_free() on the return result when you no
  * longer require it.
+ *
+ * Returns: a new #GvdbTable, or %NULL
  **/
 GvdbTable *
 gvdb_table_get_table (GvdbTable   *file,
@@ -703,13 +710,14 @@
 /**
  * gvdb_table_is_valid:
  * @table: a #GvdbTable
- * @returns: %TRUE if @table is still valid
  *
  * Checks if the table is still valid.
  *
  * An on-disk GVDB can be marked as invalid.  This happens when the file
  * has been replaced.  The appropriate action is typically to reopen the
  * file.
+ *
+ * Returns: %TRUE if @table is still valid
  **/
 gboolean
 gvdb_table_is_valid (GvdbTable *table)