fs: encode_fh: return FILEID_INVALID if invalid fid_type

This patch is a follow up on below patch:

[PATCH] exportfs: add FILEID_INVALID to indicate invalid fid_type
commit: 216b6cbdcbd86b1db0754d58886b466ae31f5a63

Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com>
Signed-off-by: Vivek Trivedi <t.vivek@samsung.com>
Acked-by: Steven Whitehouse <swhiteho@redhat.com>
Acked-by: Sage Weil <sage@inktank.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/fs/ocfs2/export.c b/fs/ocfs2/export.c
index 322216a..2965116 100644
--- a/fs/ocfs2/export.c
+++ b/fs/ocfs2/export.c
@@ -195,11 +195,11 @@
 
 	if (parent && (len < 6)) {
 		*max_len = 6;
-		type = 255;
+		type = FILEID_INVALID;
 		goto bail;
 	} else if (len < 3) {
 		*max_len = 3;
-		type = 255;
+		type = FILEID_INVALID;
 		goto bail;
 	}