Return an error if a name is too long for JFFS2 rather than
corrupting data.

Signed-off-by: Richard Purdie <rpurdie@rpsys.net>

--- linux2/fs/jffs2/dir.c~rp-jffs2-longfilename-r0.patch
+++ linux2/fs/jffs2/dir.c
@@ -88,6 +88,9 @@
 
 	D1(printk(KERN_DEBUG "jffs2_lookup()\n"));
 
+	if (target->d_name.len > JFFS2_MAX_NAME_LEN)
+		return ERR_PTR(-ENAMETOOLONG);
+
 	dir_f = JFFS2_INODE_INFO(dir_i);
 	c = JFFS2_SB_INFO(dir_i->i_sb);