Fixes: signed integer overflow: 1111111111111111111 * 10 cannot be represented in type 'long'
Fixes: 26892/clusterfuzz-testcase-minimized-ffmpeg_dem_TEDCAPTIONS_fuzzer-5756045055754240
Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
(cherry picked from commit b0f8586ca9853ab3d324ccd3c42bad4375000b0a)
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>