smb311: remove dead code for non compounded posix query info

Although we may need this in some cases in the future, remove the
currently unused, non-compounded version of POSIX query info,
SMB11_posix_query_info (instead smb311_posix_query_path_info is now
called e.g. when revalidating dentries or retrieving info for getattr)

Addresses-Coverity: 1495708 ("Resource leaks")
Signed-off-by: Steve French <stfrench@microsoft.com>