repair the variable name bug

examples/voxceleb/sv0/run.sh

 #!/bin/bash
 . ./path.sh
 set -e
-export PPAUDIO_HOME=/home/users/xiongxinlei/exprts/v3
+
 dir=./data/
 mkdir -p ${dir}
-# you can set the variable DATA_HOME to specifiy the downloaded the vox1 and vox2 dataset
+# you can set the variable PPAUDIO_HOME to specifiy the downloaded the vox1 and vox2 dataset
 python3 \
      local/train.py \
      --data-dir ${dir}