USB: remove duplicated #include

Remove duplicated #include('s) in
  drivers/usb/core/hcd.c

Signed-off-by: Huang Weiyi <weiyi.huang@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

diff --git a/drivers/usb/core/hcd.c b/drivers/usb/core/hcd.c
index 4a24843..38d4700 100644
--- a/drivers/usb/core/hcd.c
+++ b/drivers/usb/core/hcd.c
@@ -38,7 +38,6 @@
 #include <asm/unaligned.h>
 #include <linux/platform_device.h>
 #include <linux/workqueue.h>
-#include <linux/mutex.h>
 #include <linux/pm_runtime.h>
 
 #include <linux/usb.h>