Ensure that getpwent() is used in setpwent(), getpwent(),

endpwend() sequences (ditto for getgrent(), getspent(), and
getsgent()). The only real (minor) issue was in login, which kept
the passwd file open.
* libmisc/entry.c: Remove unneeded setspent() and endspent() (only
  getspnam is called in the middle).
* libmisc/find_new_ids.c: Make sure to close the password and
  group files with endpwent() and endgrent().
* libmisc/pwdcheck.c: Remove unneeded endspent() (only getspnam()
  is called before).
* src/lastlog.c, src/passwd.c, src/groupmod.c, src/faillog.c,
  src/groups.c: Make sure to close
  the password file with endpwent().
* src/login.c: Remove unneeded setpwent() (only xgetpwnam is
  called before).
* src/login.c, src/newgrp.c: Fix typos in comments.

src/groupmod.c

@@ -547,6 +547,7 @@ void update_primary_groups (gid_t ogid, gid_t ngid)
 			}
 		}
 	}
+	endpwent ();
 }
 
 /*