[patch] usb: gadget: gr_udc: debugfs functions return NULL on error

[Dan Carpenter <dan.carpenter@oracle.com>]

Debugfs functions return NULL on error.  They return an ERR_PTR if you
don't have debugfs configured.

The way it's designed is that normally you are only supposed to test for
NULL.  In this code, if "dev->dfs_root" is an ERR_PTR then passing it to
debugfs_create_file() will not cause a problem because
debugfs_create_file() would also just a stub.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>

diff --git a/drivers/usb/gadget/gr_udc.c b/drivers/usb/gadget/gr_udc.c
index 5f9c65959dd2..b34a52171568 100644
--- a/drivers/usb/gadget/gr_udc.c
+++ b/drivers/usb/gadget/gr_udc.c
@@ -226,13 +226,13 @@ static void gr_dfs_create(struct gr_udc *dev)
 	const char *name = "gr_udc_state";
 
 	dev->dfs_root = debugfs_create_dir(dev_name(dev->dev), NULL);
-	if (IS_ERR(dev->dfs_root)) {
+	if (!dev->dfs_root) {
 		dev_err(dev->dev, "Failed to create debugfs directory\n");
 		return;
 	}
 	dev->dfs_state = debugfs_create_file(name, 0444, dev->dfs_root,
 					     dev, &gr_dfs_fops);
-	if (IS_ERR(dev->dfs_state))
+	if (!dev->dfs_state)
 		dev_err(dev->dev, "Failed to create debugfs file %s\n", name);
 }