Description of problem:

grpck always fails with errors like "shadow group bin: no user oot".

Version-Release number of selected component (if applicable):
4.0.3-56

How reproducible:
always

Steps to Reproduce:
1. run "grpck"
2. don't let it "fix" the gshadow file
3.
  
Actual results:

#grpck
shadow group bin: no user oot
delete member `oot'? n
shadow group daemon: no user
delete member `'? n
shadow group daemon: no user
delete member `'? n
shadow group daemon: no user ot
delete member `ot'? n
shadow group daemon: no user in
delete member `in'? n
shadow group sys: no user oot
delete member `oot'? n
shadow group sys: no user t