Fix incorrect function pointer definition.

No call was made using this prototype directly so this just fixes
compiler warnings.


git-svn-id: svn://svn.mplayerhq.hu/mplayer/trunk@21179 b3059339-0415-0410-9bf9-f77b7e298cf2

libmpcodecs/vf.h

@@ -44,7 +44,7 @@ typedef struct vf_instance_s {
         unsigned char** src, int* stride, int w,int h, int x, int y);
     void (*uninit)(struct vf_instance_s* vf);
 
-    void (*continue_buffered_image)(struct vf_instance_s* vf);
+    int (*continue_buffered_image)(struct vf_instance_s* vf);
     // caps:
     unsigned int default_caps; // used by default query_format()
     unsigned int default_reqs; // used by default config()