Fix typo: AR(0) -> AR(1)
Fix typo: AR(0) -> AR(1)

Signed-off-by: Jean-Marc Valin <b20cab4bda6e09296359e6832b28734b973923d8@jmvalin.ca>

xiphmont/daala,KyleSiefring/daala,jmvalin/daala,xiph/daala,luctrudeau/daala,xiph/daala,KyleSiefring/daala,jmvalin/daala,HeadhunterXamd/daala,KyleSiefring/daala,ycho/daala,ycho/daala,HeadhunterXamd/daala,kodabb/daala,jmvalin/daala,HeadhunterXamd/daala,kodabb/daala,kodabb/daala,xiph/daala,ycho/daala,xiphmont/daala,luctrudeau/daala,xiphmont/daala,luctrudeau/daala,xiphmont/daala,kodabb/daala,jmvalin/daala,jmvalin/daala,xiphmont/daala,KyleSiefring/daala,HeadhunterXamd/daala,luctrudeau/daala,xiph/daala,luctrudeau/daala,HeadhunterXamd/daala,kodabb/daala,KyleSiefring/daala,ycho/daala,xiph/daala,ycho/daala