Revert "avutil/timecode: fix sscanf format string with garbage at the end"

This reverts commit 6696a07ac6.

It is wrong to restrict timecodes to always contain leading zeros or for hours
or frames to be 2 chars only.

Signed-off-by: Marton Balint <cus@passwd.hu>

libavutil/timecode.c

@@ -252,7 +252,7 @@ int av_timecode_init_from_string(AVTimecode *tc, AVRational rate, const char *st
     char c;
     int hh, mm, ss, ff, flags;
 
-    if (sscanf(str, "%02u:%02u:%02u%c%02u", &hh, &mm, &ss, &c, &ff) != 5) {
+    if (sscanf(str, "%d:%d:%d%c%d", &hh, &mm, &ss, &c, &ff) != 5) {
         av_log(log_ctx, AV_LOG_ERROR, "Unable to parse timecode, "
                                       "syntax: hh:mm:ss[:;.]ff\n");
         return AVERROR_INVALIDDATA;