usb: devio: Fixed macro parenthesis error

This patch fixes error 'Macros with complex values should be enclosed in
parenthesis' in USB/devio.c

Signed-off-by: Tülin İzer <tulinizer@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/drivers/usb/core/devio.c b/drivers/usb/core/devio.c
index 9374937..009bc3f 100644
--- a/drivers/usb/core/devio.c
+++ b/drivers/usb/core/devio.c
@@ -56,7 +56,7 @@
 #include "usb.h"
 
 #define USB_MAXBUS			64
-#define USB_DEVICE_MAX			USB_MAXBUS * 128
+#define USB_DEVICE_MAX			(USB_MAXBUS * 128)
 #define USB_SG_SIZE			16384 /* split-size for large txs */
 
 /* Mutual exclusion for removal, open, and release */