Add the function declaration of ff_svq1_packet_checksum to svq1.h and include

svq1.h where this function is used. Fixes the warning:
libavcodec/svq3.c:862: warning: implicit declaration of function ‘ff_svq1_packet_checksum’

Originally committed as revision 15737 to svn://svn.ffmpeg.org/ffmpeg/trunk

libavcodec/svq1.h

@@ -47,6 +47,9 @@ typedef struct {
     int height;
 } svq1_frame_size_t;
 
+uint16_t ff_svq1_packet_checksum (const uint8_t *data, const int length,
+                                  int value);
+
 extern const int8_t* const ff_svq1_inter_codebooks[6];
 extern const int8_t* const ff_svq1_intra_codebooks[6];
 

libavcodec/svq3.c

@@ -44,6 +44,8 @@
 #include <zlib.h>
 #endif
 
+#include "svq1.h"
+
 /**
  * @file svq3.c
  * svq3 decoder.