lavfi: reorder AVFilterContext fields.

Place related fields together, remove holes.

libavfilter/avfilter.h

@@ -417,22 +417,21 @@ struct AVFilterContext {
 
     char *name;                     ///< name of this filter instance
 
+    AVFilterPad   *input_pads;      ///< array of input pads
+    AVFilterLink **inputs;          ///< array of pointers to input links
 #if FF_API_FOO_COUNT
     unsigned input_count;           ///< @deprecated use nb_inputs
 #endif
-    AVFilterPad   *input_pads;      ///< array of input pads
-    AVFilterLink **inputs;          ///< array of pointers to input links
+    unsigned    nb_inputs;          ///< number of input pads
 
+    AVFilterPad   *output_pads;     ///< array of output pads
+    AVFilterLink **outputs;         ///< array of pointers to output links
 #if FF_API_FOO_COUNT
     unsigned output_count;          ///< @deprecated use nb_outputs
 #endif
-    AVFilterPad   *output_pads;     ///< array of output pads
-    AVFilterLink **outputs;         ///< array of pointers to output links
+    unsigned    nb_outputs;         ///< number of output pads
 
     void *priv;                     ///< private data for use by the filter
-
-    unsigned nb_inputs;             ///< number of input pads
-    unsigned nb_outputs;            ///< number of output pads
 };
 
 /**