Use enum PixelFormat to silence one icc warning:

warning #188: enumerated type mixed with another type
      enum PixelFormat pix_fmts[] = { c->pix_fmt, PIX_FMT_NONE };
                                      ^


git-svn-id: file:///var/local/repositories/ffmpeg/trunk@23640 9553f0bf-9b14-0410-a0b8-cfaf0461ba5b

libavfilter/vsrc_buffer.c

@@ -26,7 +26,8 @@ typedef struct {
     int64_t           pts;
     AVFrame           frame;
     int               has_frame;
-    int               h, w, pix_fmt;
+    int               h, w;
+    enum PixelFormat  pix_fmt;
     AVRational        pixel_aspect;
 } BufferSourceContext;