Fix PKINIT memory leaks

pkinit_client_process() calls pkinit_client_profile() a second time,
leaking the values obtained the first time.  Remove the call.

Commit 13ae08e70a05768d4f65978ce1a8d4e16fec0d35 introduced more
possibilities for process_option_identity() to return failure after it
filled in some fields.  PKCS11 option parsing already prevents leaks
by freeing old values before setting new ones; do so in the other
option-parsing functions as well.

https://github.com/krb5/krb5/commit/aee8a823db095eda5842420e917fe7a664a0e7af
Author: Greg Hudson <ghudson@mit.edu>
Commit: aee8a823db095eda5842420e917fe7a664a0e7af
Branch: master
 src/plugins/preauth/pkinit/pkinit_clnt.c     |    2 --
 src/plugins/preauth/pkinit/pkinit_identity.c |    5 +++++
 2 files changed, 5 insertions(+), 2 deletions(-)