smb3: limit noisy error

For servers which don't support copy_range (SMB3 CopyChunk), the
logging of:
 CIFS: VFS: \\server\share refcpy ioctl error -95 getting resume key
can fill the client logs and make debugging real problems more
difficult.  Change the -EOPNOTSUPP on copy_range to a "warn once"
Signed-off-by: Steve French <stfrench@microsoft.com>

fs/cifs/smb2ops.c

@@ -1567,7 +1567,10 @@ SMB2_request_res_key(const unsigned int xid, struct cifs_tcon *tcon,
 			NULL, 0 /* no input */, CIFSMaxBufSize,
 			(char **)&res_key, &ret_data_len);
 
-	if (rc) {
+	if (rc == -EOPNOTSUPP) {
+		pr_warn_once("Server share %s does not support copy range\n", tcon->treeName);
+		goto req_res_key_exit;
+	} else if (rc) {
 		cifs_tcon_dbg(VFS, "refcpy ioctl error %d getting resume key\n", rc);
 		goto req_res_key_exit;
 	}