avcodec: fix whitespace on AVPanScan struct definition

libavcodec/avcodec.h

@@ -1049,7 +1049,7 @@ typedef struct RcOverride{
  * This specifies the area which should be displayed.
  * Note there may be multiple such areas for one frame.
  */
-typedef struct AVPanScan{
+typedef struct AVPanScan {
     /**
      * id
      * - encoding: Set by user.
@@ -1071,7 +1071,7 @@ typedef struct AVPanScan{
      * - decoding: Set by libavcodec.
      */
     int16_t position[3][2];
-}AVPanScan;
+} AVPanScan;
 
 /**
  * This structure describes the bitrate properties of an encoded bitstream. It