CIFS: remove bad_network_name flag

STATUS_BAD_NETWORK_NAME can be received during node failover,
causing the flag to be set and making the reconnect thread
always unsuccessful, thereafter.

Once the only place where it is set is removed, the remaining
bits are rendered moot.

Removing it does not prevent "mount" from failing when a non
existent share is passed.

What happens when the share really ceases to exist while the
share is mounted is undefined now as much as it was before.

Signed-off-by: Germano Percossi <germano.percossi@citrix.com>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
CC: Stable <stable@vger.kernel.org>
Signed-off-by: Steve French <smfrench@gmail.com>

fs/cifs/cifsglob.h

@@ -948,7 +948,6 @@ struct cifs_tcon {
 	bool use_persistent:1; /* use persistent instead of durable handles */
 #ifdef CONFIG_CIFS_SMB2
 	bool print:1;		/* set if connection to printer share */
-	bool bad_network_name:1; /* set if ret status STATUS_BAD_NETWORK_NAME */
 	__le32 capabilities;
 	__u32 share_flags;
 	__u32 maximal_access;

fs/cifs/smb2pdu.c

@@ -1171,9 +1171,6 @@ SMB2_tcon(const unsigned int xid, struct cifs_ses *ses, const char *tree,
 	else
 		return -EIO;
 
-	if (tcon && tcon->bad_network_name)
-		return -ENOENT;
-
 	unc_path = kmalloc(MAX_SHARENAME_LENGTH * 2, GFP_KERNEL);
 	if (unc_path == NULL)
 		return -ENOMEM;
@@ -1277,8 +1274,6 @@ tcon_exit:
 tcon_error_exit:
 	if (rsp->hdr.sync_hdr.Status == STATUS_BAD_NETWORK_NAME) {
 		cifs_dbg(VFS, "BAD_NETWORK_NAME: %s\n", tree);
-		if (tcon)
-			tcon->bad_network_name = true;
 	}
 	goto tcon_exit;
 }