back-port r19749 from trunk

 If mkstemp() is available, the new ccache file gets created but the
 subsequent open(O_CREAT|O_EXCL) call fails because the file was
 already created by mkstemp().  Apply patch from Apple to keep the file
 descriptor open.


Commit By: tlyu



Revision: 19750
Changed Files:
_U  branches/krb5-1-6/
U   branches/krb5-1-6/src/lib/krb5/ccache/cc_file.c