avformat/nistspheredec: fix silly bug

Signed-off-by: Paul B Mahol <onemda@gmail.com>

libavformat/nistspheredec.c

@@ -112,7 +112,7 @@ static int nist_read_header(AVFormatContext *s)
             sscanf(buffer, "%*s %*s %"SCNd32, &st->codec->bits_per_coded_sample);
         } else {
             char key[32], value[32];
-            if (sscanf(buffer, "%31s %*s %31s", key, value) == 3) {
+            if (sscanf(buffer, "%31s %*s %31s", key, value) == 2) {
                 av_dict_set(&s->metadata, key, value, AV_DICT_APPEND);
             } else {
                 av_log(s, AV_LOG_ERROR, "Failed to parse '%s' as metadata\n", buffer);