Check out https://kb.netapp.com/support/index?page=content&id=2011558. Try troubleshooting the ssh connection with -v, -vv, or -vvv from the client. If all you want to do is quiet it down, you can modify the syslog config - though I'd try to fix the issue instead.
This means the first SSH key offered by client is not the same as stored in filer, so it just goes on an tries next key offered. The message is debug level in OpenSSH, but someone in NetApp decided to promote it to info level.
The only fix is to make sure client is using the same public key as is stored on NetApp.