[GFS2] BZ 217008 fsfuzzer fix.

Update the quilt header comments to match the
code changes.

Change gfs2_lookup_simple to return an error in the case
of a NULL inode.
The callers of gfs2_lookup_simple do not check for NULL
in the no entry case and such would end up dereferencing a NULL ptr.

This fixes:
http://projects.info-pull.com/mokb/MOKB-15-11-2006.html

Signed-off-by: Russell Cattelan <cattelan@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

fs/gfs2/inode.c

@@ -361,8 +361,18 @@ int gfs2_change_nlink(struct gfs2_inode *ip, int diff)
 struct inode *gfs2_lookup_simple(struct inode *dip, const char *name)
 {
 	struct qstr qstr;
+	struct inode *inode;
 	gfs2_str2qstr(&qstr, name);
-	return gfs2_lookupi(dip, &qstr, 1, NULL);
+	inode = gfs2_lookupi(dip, &qstr, 1, NULL);
+	/* gfs2_lookupi has inconsistent callers: vfs
+	 * related routines expect NULL for no entry found,
+	 * gfs2_lookup_simple callers expect ENOENT
+	 * and do not check for NULL.
+	 */
+	if (inode == NULL)
+		return ERR_PTR(-ENOENT);
+	else
+		return inode;
 }