usb: dwc3: debugfs: add a kfree() on error to dwc3_testmode_open()

We may as well fix this potential leak so we don't have to listen to
the static checkers complain.

Signed-off-by: Dan Carpenter <error27@gmail.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>
diff --git a/drivers/usb/dwc3/debugfs.c b/drivers/usb/dwc3/debugfs.c
index 432df53..dd861c4 100644
--- a/drivers/usb/dwc3/debugfs.c
+++ b/drivers/usb/dwc3/debugfs.c
@@ -445,8 +445,10 @@
 	if (!buf0)
 		return -ENOMEM;
 	buf1 = kmalloc(BUF_SIZE, GFP_KERNEL);
-	if (!buf1)
+	if (!buf1) {
+		kfree(buf0);
 		return -ENOMEM;
+	}
 
 	memset(buf0, 0xaa, BUF_SIZE);
 	memset(buf1, 0x33, BUF_SIZE);