[vala/wip/sdl2] SDL2_image: Fix issues

[Rico Tzschichholz <ricotz src gnome org>]

commit 9592b2da086baee30deea0d2d7e8716284461419
Author: Rico Tzschichholz <ricotz ubuntu com>
Date:   Tue Jan 26 19:49:12 2021 +0100

    SDL2_image: Fix issues

 vapi/SDL2_image.vapi | 7 ++-----
 1 file changed, 2 insertions(+), 5 deletions(-)
---
diff --git a/vapi/SDL2_image.vapi b/vapi/SDL2_image.vapi
index ff1495a59..a4d896cf9 100644
--- a/vapi/SDL2_image.vapi
+++ b/vapi/SDL2_image.vapi
@@ -44,7 +44,7 @@ namespace SDLImage {
        //! General
 
        [CCode (cname = "IMG_Linked_Version")]
-       public static unowned SDL.Version linked ();
+       public static unowned SDL.Version? linked ();
 
        [CCode (cname = "IMG_Init")]
        public static int init (int flags);
@@ -72,9 +72,6 @@ namespace SDLImage {
        [CCode (cname = "IMG_LoadTextureTyped_RW")]
        public static SDL.Video.Texture? load_texture_rw_typed (SDL.Video.Renderer renderer, SDL.RWops src, 
bool freesrc, string type);
 
-       [CCode (cname = "IMG_InvertAlpha")]
-       public static int invert_alpha (int on);
-
        [CCode (cname = "IMG_LoadCUR_RW")]
        public static SDL.Video.Surface? load_cur (SDL.RWops src);
 
@@ -121,7 +118,7 @@ namespace SDLImage {
        public static SDL.Video.Surface? load_webp (SDL.RWops src);
 
        [CCode (cname = "IMG_ReadXPMFromArray")]
-       public static SDL.Video.Surface? read_xpm (string[] xpmdata);
+       public static SDL.Video.Surface? read_xpm ([CCode (array_length = false)] uint8[] xpmdata);
 
        [CCode (cname = "IMG_SavePNG")]
        public static int save_as_png (SDL.Video.Surface surface, string file);