IB/ipath: Check return value of lookup_one_len

This fixes kernel.org bug 8003.
Signed-off-by: Bryan O'Sullivan <bryan.osullivan@qlogic.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>

drivers/infiniband/hw/ipath/ipath_fs.c

@@ -451,12 +451,18 @@ static int create_device_files(struct super_block *sb,
 	return ret;
 }
 
-static void remove_file(struct dentry *parent, char *name)
+static int remove_file(struct dentry *parent, char *name)
 {
 	struct dentry *tmp;
+	int ret;
 
 	tmp = lookup_one_len(name, parent, strlen(name));
 
+	if (IS_ERR(tmp)) {
+		ret = PTR_ERR(tmp);
+		goto bail;
+	}
+
 	spin_lock(&dcache_lock);
 	spin_lock(&tmp->d_lock);
 	if (!(d_unhashed(tmp) && tmp->d_inode)) {
@@ -469,6 +475,14 @@ static void remove_file(struct dentry *parent, char *name)
 		spin_unlock(&tmp->d_lock);
 		spin_unlock(&dcache_lock);
 	}
+
+	ret = 0;
+bail:
+	/*
+	 * We don't expect clients to care about the return value, but
+	 * it's there if they need it.
+	 */
+	return ret;
 }
 
 static int remove_device_files(struct super_block *sb,