smb: client: fix return value of parse_dfs_referrals()

Return -ENOENT in parse_dfs_referrals() when server returns no targets
for a referral request as specified in

  MS-DFSC 3.1.5.4.3 Receiving a Root Referral Response or Link
  Referral Response:

    > If the referral request is successful, but the NumberOfReferrals
    > field in the referral header (as specified in section 2.2.4) is
    > 0, the DFS server could not find suitable targets to return to
    > the client.  In this case, the client MUST fail the original I/O
    > operation with STATUS_OBJECT_PATH_NOT_FOUND.

Signed-off-by: Paulo Alcantara (Red Hat) <pc@manguebit.com>
Signed-off-by: Steve French <stfrench@microsoft.com>