Thie fixes the following error.

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make.exe[1]: Entering directory `F:/lang/work/vlc/vlc.git/modules/access_output'
  CC     libaccess_output_file_plugin_la-file.lo
file.c: In function 'Open':
file.c:142: error: 'STDOUT_FILENO' undeclared (first use in this function)
file.c:142: error: (Each undeclared identifier is reported only once
file.c:142: error: for each function it appears in.)
make.exe[1]: *** [libaccess_output_file_plugin_la-file.lo] Error 1
make.exe[1]: Leaving directory `F:/lang/work/vlc/vlc.git/modules/access_output'
make.exe: *** [all] Error 2
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Signed-off-by: Rémi Denis-Courmont <remi@remlab.net>