cifs: do not attempt cifs operation on smb2+ rename error

A path-based rename returning EBUSY will incorrectly try opening
the file with a cifs (NT Create AndX) operation on an smb2+ mount,
which causes the server to force a session close.

If the mount is smb2+, skip the fallback.

Signed-off-by: Frank Sorenson <sorenson@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
CC: Stable <stable@vger.kernel.org>
Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com>