desc_81: Fix compilation with older compilers

The attached fixes the following error when compiling 'dvblastctl'

  /usr/local/include/bitstream/atsc/si/desc_81.h: In function ‘desc81_bit_rate_code_from_octetrate’:
  /usr/local/include/bitstream/atsc/si/desc_81.h:83:5: error: ‘for’ loop initial declarations are only allowed in C99 mode
  /usr/local/include/bitstream/atsc/si/desc_81.h:83:5: note: use option -std=c99 or -std=gnu99 to compile your code

Apply via 'git am 0001-desc_81-Fix-compilation-with-older-compilers.patch'
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Status Job ID Name Coverage
  Test
failed #470958
amd64 docker
test

00:00:09

 
Name Stage Failure
failed
test Test There has been a runner system failure, please try again
ERROR: The registry.videolan.org/videolan-base-xenial is not present on list of allowed images
- registry.videolan.org:5000/*:*
- registry.videolan.org/*:*
- codechecker:bar

Please check runner's configuration: http://doc.gitlab.com/ci/docker/using_docker_images.html#overwrite-image-and-services
ERROR: Preparation failed: invalid image
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ERROR: Job failed (system failure): invalid image