xhci: Fix warning introduced by disabling runtime PM.

The 0day build server caught a new build warning that is triggered when
CONFIG_USB_DEFAULT_PERSIST is turned on:

tree:   git://git.kernel.org/pub/scm/linux/kernel/git/sarah/xhci.git for-usb-next
head:   0730d52a86
commit: c8476fb855 [1/3] usb: xhci: Disable runtime PM suspend for quirky controllers
config: i386-randconfig-r6-0826 (attached as .config)

All warnings:

   drivers/usb/host/xhci.c: In function 'xhci_free_dev':
>> drivers/usb/host/xhci.c:3560:17: warning: unused variable 'dev' [-Wunused-variable]
     struct device *dev = hcd->self.controller;
                    ^
   drivers/usb/host/xhci.c: In function 'xhci_alloc_dev':
>> drivers/usb/host/xhci.c:3648:17: warning: unused variable 'dev' [-Wunused-variable]
     struct device *dev = hcd->self.controller;
                    ^

vim +/dev +3560 drivers/usb/host/xhci.c

  3554   * disabled.  Free any HC data structures associated with that device.
  3555   */
  3556  void xhci_free_dev(struct usb_hcd *hcd, struct usb_device *udev)
  3557  {
  3558          struct xhci_hcd *xhci = hcd_to_xhci(hcd);
  3559          struct xhci_virt_device *virt_dev;
> 3560          struct device *dev = hcd->self.controller;
  3561          unsigned long flags;
  3562          u32 state;
  3563          int i, ret;
  3564
  3565  #ifndef CONFIG_USB_DEFAULT_PERSIST
  3566          /*
  3567           * We called pm_runtime_get_noresume when the device was attached.
  3568           * Decrement the counter here to allow controller to runtime suspend
  3569           * if no devices remain.
  3570           */
  3571          if (xhci->quirks & XHCI_RESET_ON_RESUME)
  3572                  pm_runtime_put_noidle(dev);
  3573  #endif
  3574
...
  3641  /*
  3642   * Returns 0 if the xHC ran out of device slots, the Enable Slot command
  3643   * timed out, or allocating memory failed.  Returns 1 on success.
  3644   */
  3645  int xhci_alloc_dev(struct usb_hcd *hcd, struct usb_device *udev)
  3646  {
  3647          struct xhci_hcd *xhci = hcd_to_xhci(hcd);
> 3648          struct device *dev = hcd->self.controller;
  3649          unsigned long flags;
  3650          int timeleft;
  3651          int ret;

Fix this.

Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Cc: Shawn Nematbakhsh <shawnn@chromium.org>

drivers/usb/host/xhci.c

@@ -3557,7 +3557,6 @@ void xhci_free_dev(struct usb_hcd *hcd, struct usb_device *udev)
 {
 	struct xhci_hcd *xhci = hcd_to_xhci(hcd);
 	struct xhci_virt_device *virt_dev;
-	struct device *dev = hcd->self.controller;
 	unsigned long flags;
 	u32 state;
 	int i, ret;
@@ -3569,7 +3568,7 @@ void xhci_free_dev(struct usb_hcd *hcd, struct usb_device *udev)
 	 * if no devices remain.
 	 */
 	if (xhci->quirks & XHCI_RESET_ON_RESUME)
-		pm_runtime_put_noidle(dev);
+		pm_runtime_put_noidle(hcd->self.controller);
 #endif
 
 	ret = xhci_check_args(hcd, udev, NULL, 0, true, __func__);
@@ -3645,7 +3644,6 @@ static int xhci_reserve_host_control_ep_resources(struct xhci_hcd *xhci)
 int xhci_alloc_dev(struct usb_hcd *hcd, struct usb_device *udev)
 {
 	struct xhci_hcd *xhci = hcd_to_xhci(hcd);
-	struct device *dev = hcd->self.controller;
 	unsigned long flags;
 	int timeleft;
 	int ret;
@@ -3705,7 +3703,7 @@ int xhci_alloc_dev(struct usb_hcd *hcd, struct usb_device *udev)
 	 * suspend if there is a device attached.
 	 */
 	if (xhci->quirks & XHCI_RESET_ON_RESUME)
-		pm_runtime_get_noresume(dev);
+		pm_runtime_get_noresume(hcd->self.controller);
 #endif
 
 	/* Is this a LS or FS device under a HS hub? */