Fixup a couple of trivials doc warnings.

Correct the 'Returns' statement to match what gtk-doc expects.

src/cairo-cache.c

@@ -92,6 +92,7 @@ _cairo_cache_fini (cairo_cache_t *cache)
  * @keys_equal: a function to return %TRUE if two keys are equal
  * @entry_destroy: destroy notifier for cache entries
  * @max_size: the maximum size for this cache
+ * Returns: the newly created #cairo_cache_t
  *
  * Creates a new cache using the keys_equal() function to determine
  * the equality of entries.
@@ -119,8 +120,6 @@ _cairo_cache_fini (cairo_cache_t *cache)
  * _cairo_cache_freeze() and _cairo_cache_thaw() calls can be
  * used to establish a window during which no automatic removal of
  * entries will occur.
- *
- * Return value:
  **/
 cairo_cache_t *
 _cairo_cache_create (cairo_cache_keys_equal_func_t keys_equal,

src/cairo-pattern.c

@@ -1663,11 +1663,10 @@ _cairo_pattern_is_opaque (const cairo_pattern_t *abstract_pattern)
 }
 
 /**
- * _cairo_pattern_analyze_filter
+ * _cairo_pattern_analyze_filter:
  * @pattern: surface pattern
  * @pad_out: location to store necessary padding in the source image, or %NULL
- *
- * Returns the optimized #cairo_filter_t to use with @pattern.
+ * Returns: the optimized #cairo_filter_t to use with @pattern.
  *
  * Analyze the filter to determine how much extra needs to be sampled
  * from the source image to account for the filter radius and whether