Make ff_add_wav static to ra144.c

Signed-off-by: Janne Grunau <janne-ffmpeg@jannau.net>
(cherry picked from commit 1a886748)

libavcodec/ra144.c

@@ -1503,7 +1503,7 @@ const int16_t * const ff_lpc_refl_cb[10]={
     lpc_refl_cb6, lpc_refl_cb7, lpc_refl_cb8, lpc_refl_cb9, lpc_refl_cb10
 };
 
-void ff_add_wav(int16_t *dest, int n, int skip_first, int *m, const int16_t *s1,
+static void ff_add_wav(int16_t *dest, int n, int skip_first, int *m, const int16_t *s1,
                        const int8_t *s2, const int8_t *s3)
 {
     int i;

libavcodec/ra144.h

@@ -56,8 +56,6 @@ typedef struct {
     uint16_t adapt_cb[146+2];
 } RA144Context;
 
-void ff_add_wav(int16_t *dest, int n, int skip_first, int *m, const int16_t *s1,
-                const int8_t *s2, const int8_t *s3);
 void ff_copy_and_dup(int16_t *target, const int16_t *source, int offset);
 int ff_eval_refl(int *refl, const int16_t *coefs, AVCodecContext *avctx);
 void ff_eval_coefs(int *coefs, const int *refl);