usb: dwc3: fix a warning

The previous patch left an unused variable, I apologize.

Signed-off-by: Alessandro Rubini <rubini@gnudd.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
diff --git a/drivers/usb/dwc3/debugfs.c b/drivers/usb/dwc3/debugfs.c
index d9e7a26..fcfa915 100644
--- a/drivers/usb/dwc3/debugfs.c
+++ b/drivers/usb/dwc3/debugfs.c
@@ -377,7 +377,6 @@
 static int dwc3_regdump_show(struct seq_file *s, void *unused)
 {
 	struct dwc3		*dwc = s->private;
-	int			i;
 
 	seq_printf(s, "DesignWare USB3 Core Register Dump\n");
 	debugfs_print_regs32(s, dwc3_regs, ARRAY_SIZE(dwc3_regs),