PVS-Studio warning V571 for Asterisk

void *ast_sorcery_retrieve_by_fields(....)
{
  ....
  if ((flags & AST_RETRIEVE_FLAG_MULTIPLE)) {
  ....
  } else if (fields && wizard->wizard->retrieve_fields) {  //<==
      if (wizard->wizard->retrieve_fields) {               //<==
        object = wizard->wizard->retrieve_fields(....);
      }
  }
}

This suspicious code was found in Asterisk project by PVS-Studio static code analyzer.
Warning message is:
V571 Recurring check. The 'wizard->wizard->retrieve_fields' condition was already verified in line 1520. sorcery.c 1521

PVS-Studio is a static analyzer for detecting bugs in the source code of applications written in C, C++, C++11, C++/CX. Site: http://www.viva64.com/en/pvs-studio/