udf: bug on exotic flag in udf_get_filename()

UDF volume is only mounted with UDF_FLAG_UTF8
or UDF_FLAG_NLS_MAP (see fill udf_fill_super().
BUG() if we have something different in udf_get_filename()

Suggested-by: Jan Kara <jack@suse.cz>
Signed-off-by: Fabian Frederick <fabf@skynet.be>
Signed-off-by: Jan Kara <jack@suse.cz>

fs/udf/unicode.c

@@ -365,7 +365,7 @@ int udf_get_filename(struct super_block *sb, uint8_t *sname, int slen,
 			goto out2;
 		}
 	} else
-		goto out2;
+		BUG();
 
 	ret = udf_translate_to_linux(dname, dlen,
 				     filename->u_name, filename->u_len,