[krbdev.mit.edu #6377] SVN Commit

[Ken Raeburn via RT]

This makes them safer to call in various contexts where NULL may leak
through, and makes analysis easier.

Also, remove some checks for NULL before calling a free routine that
will also check for NULL.

http://src.mit.edu/fisheye/changelog/krb5/?cs=21920
Commit By: raeburn
Revision: 21920
Changed Files:
U   trunk/src/lib/krb5/krb/free_rtree.c
U   trunk/src/lib/krb5/krb/init_ctx.c
U   trunk/src/lib/krb5/krb/kfree.c
U   trunk/src/lib/krb5/krb/preauth2.c
U   trunk/src/lib/krb5/os/free_krbhs.c
U   trunk/src/lib/krb5/os/promptusr.c