[krbdev.mit.edu #3218] kdb5_util load requires that the dumpfile be writable.

[Alexandra Ellwood via RT]

kdb5_util load requires that the dumpfile be writable.  This is lame since one may want to 
restore one's database from read-only backup media (such as a CD).

The code responsible for this bug is in krb5/src/kadmin/dbutil/dump.c in load_db().  I believe 
the dumpfile is only being opened read/write so it can be locked.   If the file is read-only you 
shouldn't need to lock it so this should not be a fatal error.