Fix PKINIT memory leaks

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.

ticket: 8991 (new)