common/quota: sort lines of repquota output

common/quota: sort lines of repquota output

The golden image of some cases (e.g: generic/305 generic/326
generic/327 generic/328 xfs/214 xfs/330 and xfs/440) depend on the
output of repquota() function.

When it reports multi-users, we can't control the order of lines,
then always hit failures likes:

  ...
   Create the original files
  -root 3072 0 0
   nobody 0 0 0
   fsgqa 0 0 0
  +root 3072 0 0
  ...

So sort the lines to make sure it won't break the golden image.

Signed-off-by: Zorro Lang <zlang@redhat.com>
Reviewed-by: Eryu Guan <guaneryu@gmail.com>
Signed-off-by: Eryu Guan <guaneryu@gmail.com>