riff: Make ff_riff_tags static and move under appropriate #ifdef

The table is not used outside the file.

libavformat/riff.c

@@ -367,13 +367,6 @@ const AVMetadataConv ff_riff_info_conv[] = {
     { 0 },
 };
 
-const char ff_riff_tags[][5] = {
-    "IARL", "IART", "ICMS", "ICMT", "ICOP", "ICRD", "ICRP", "IDIM", "IDPI",
-    "IENG", "IGNR", "IKEY", "ILGT", "ILNG", "IMED", "INAM", "IPLT", "IPRD",
-    "IPRT", "ISBJ", "ISFT", "ISHP", "ISRC", "ISRF", "ITCH",
-    {0}
-};
-
 #if CONFIG_MUXERS
 int64_t ff_start_tag(AVIOContext *pb, const char *tag)
 {
@@ -575,12 +568,19 @@ void ff_riff_write_info_tag(AVIOContext *pb, const char *tag, const char *str)
     }
 }
 
+static const char riff_tags[][5] = {
+    "IARL", "IART", "ICMS", "ICMT", "ICOP", "ICRD", "ICRP", "IDIM", "IDPI",
+    "IENG", "IGNR", "IKEY", "ILGT", "ILNG", "IMED", "INAM", "IPLT", "IPRD",
+    "IPRT", "ISBJ", "ISFT", "ISHP", "ISRC", "ISRF", "ITCH",
+    {0}
+};
+
 static int riff_has_valid_tags(AVFormatContext *s)
 {
     int i;
 
-    for (i = 0; *ff_riff_tags[i]; i++) {
-        if (av_dict_get(s->metadata, ff_riff_tags[i], NULL, AV_DICT_MATCH_CASE))
+    for (i = 0; *riff_tags[i]; i++) {
+        if (av_dict_get(s->metadata, riff_tags[i], NULL, AV_DICT_MATCH_CASE))
             return 1;
     }
 
@@ -602,8 +602,8 @@ void ff_riff_write_info(AVFormatContext *s)
 
     list_pos = ff_start_tag(pb, "LIST");
     ffio_wfourcc(pb, "INFO");
-    for (i = 0; *ff_riff_tags[i]; i++) {
-        if ((t = av_dict_get(s->metadata, ff_riff_tags[i], NULL, AV_DICT_MATCH_CASE)))
+    for (i = 0; *riff_tags[i]; i++) {
+        if ((t = av_dict_get(s->metadata, riff_tags[i], NULL, AV_DICT_MATCH_CASE)))
             ff_riff_write_info_tag(s->pb, t->key, t->value);
     }
     ff_end_tag(pb, list_pos);