illumos gate

There are three warnings generated by gcc7 on OmniOS when building krb5/preauth/pkinit against OpenSSL 1.1

./pkinit_crypto_openssl.c: In function 'pkinit_choose_tokens':
../pkinit_crypto_openssl.c:3865:24: error: comparison between pointer and integer [-Werror]
             while (*cp != NULL) {
                        ^~
../pkinit_crypto_openssl.c: In function 'pkinit_open_session':
../pkinit_crypto_openssl.c:4109:36: error: initialization makes integer from pointer without a cast [-Werror=int-conversion]
     CK_SESSION_HANDLE tmpsession = NULL;
                                    ^~~~
../pkinit_crypto_openssl.c: In function 'pkinit_process_td_trusted_certifiers':
../pkinit_crypto_openssl.c:6627:6: error: this 'else' clause does not guard...  -Werror=misleading-indentation]
      else
      ^~~~
../pkinit_crypto_openssl.c:6629:3: note: ...this statement, but the latter is misleadingly indented as if it were guarded by the 'else'
   sk_X509_NAME_push(sk_xn, xn);
   ^~~~~~~~~~~~~~~~~

The last error does not show up when building against OpenSSL 1.0 since sk_X509_NAME_push is a macro in 1.0 which expands to a blank line followed by some statements - the blank line resets gcc's guard check.