../cvt/cvt.c:34:1: warning: no previous prototype for ‘cvt_is_standard’ [-Wmissing-prototypes]
   34 | cvt_is_standard(int hdisplay, int vdisplay, float vrefresh, bool reduced, bool verbose)
      | ^~~~~~~~~~~~~~~

Signed-off-by: Alan Coopersmith <alan.coopersmith@oracle.com>