PVS-Studio warning V595 for OpenSSL

int SSL_shutdown(SSL *s)
{
  if (s->handshake_func == 0)
  {
    SSLerr(SSL_F_SSL_SHUTDOWN, SSL_R_UNINITIALIZED);
    return -1;
  }

  if ((s != NULL) && !SSL_in_init(s))
    return(s->method->ssl_shutdown(s));
  else
    return(1);
  }
  ....
}

This suspicious code was found in OpenSSL project by PVS-Studio static code analyzer.
Warning message is:
V595 The 's' pointer was utilized before it was verified against nullptr. Check lines: 1013, 1019. ssl_lib.c 1013

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/