curl_schannel.c: Fixed possible memory or handle leak

First try to fix possible memory leaks, in this case:
Only connssl->ctxt xor onnssl->cred being initialized.

lib/vtls/curl_schannel.c

@@ -1145,6 +1145,7 @@ int Curl_schannel_shutdown(struct connectdata *conn, int sockindex)
               " (bytes written: %zd)\n", curl_easy_strerror(code), written);
       }
     }
+  }
 
   /* free SSPI Schannel API security context handle */
   if(connssl->ctxt) {
@@ -1169,7 +1170,6 @@ int Curl_schannel_shutdown(struct connectdata *conn, int sockindex)
       Curl_safefree(connssl->cred);
     }
   }
-  }
 
   /* free internal buffer for received encrypted data */
   if(connssl->encdata_buffer != NULL) {