avio: deprecate put_tag

it's not used internally anymore and shouldn't be public.
Signed-off-by: Ronald S. Bultje <rsbultje@gmail.com>
(cherry picked from commit 61840b43)

libavformat/avio.h

@@ -407,6 +407,7 @@ attribute_deprecated void         put_le24(AVIOContext *s, unsigned int val);
 attribute_deprecated void         put_be24(AVIOContext *s, unsigned int val);
 attribute_deprecated void         put_le16(AVIOContext *s, unsigned int val);
 attribute_deprecated void         put_be16(AVIOContext *s, unsigned int val);
+attribute_deprecated void         put_tag(AVIOContext *s, const char *tag);
 /**
  * @}
  */
@@ -443,7 +444,6 @@ void avio_wl24(AVIOContext *s, unsigned int val);
 void avio_wb24(AVIOContext *s, unsigned int val);
 void avio_wl16(AVIOContext *s, unsigned int val);
 void avio_wb16(AVIOContext *s, unsigned int val);
-void put_tag(AVIOContext *s, const char *tag);
 
 #if FF_API_OLD_AVIO
 attribute_deprecated void put_strz(AVIOContext *s, const char *buf);

libavformat/aviobuf.c

@@ -449,12 +449,14 @@ void avio_wb24(AVIOContext *s, unsigned int val)
     avio_w8(s, val);
 }
 
+#if FF_API_OLD_AVIO
 void put_tag(AVIOContext *s, const char *tag)
 {
     while (*tag) {
         avio_w8(s, *tag++);
     }
 }
+#endif
 
 /* Input stream */