image: cleanup header declaration

Signed-off-by: Julien Danjou <julien@danjou.info>

image.c

@@ -128,7 +128,7 @@ image_new_from_argb32(int width, int height, uint32_t *data)
  * \param filename The image file to load.
  * \return A new image.
  */
-image_t *
+static image_t *
 image_new_from_file(const char *filename)
 {
     Imlib_Image imimage;

image.h

@@ -56,9 +56,7 @@ image_delete(image_t **i)
 
 DO_RCNT(image_t, image, image_delete)
 
-image_t * image_new_from_file(const char *);
 image_t * image_new_from_argb32(int, int, uint32_t *);
-uint8_t * image_data_argb32_get(image_t *);
 
 int luaA_image_userdata_new(lua_State *, image_t *);