USB: core: hcd-pci: free IRQ before disabling PCI device when shutting down

The assigned IRQ should be freed before calling pci_disable_device()
when shutting down system, otherwise it will cause following warning.
[  568.879482] ------------[ cut here ]------------
[  568.884236] WARNING: CPU: 1 PID: 3300 at /home/konrad/ssd/konrad/xtt-i386/bootstrap/linux-usb/fs/proc/generic.c:521 remove_proc_entry+0x165/0x170()
[  568.897846] remove_proc_entry: removing non-empty directory 'irq/16', leaking at least 'ohci_hcd:usb4'
[  568.907430] Modules linked in: dm_multipath dm_mod iscsi_boot_sysfs iscsi_tcp libiscsi_tcp libiscsi scsi_transport_iscsi libcrc32c crc32c_generic sg sd_mod crct10dif_generic crc_t10dif crct10dif_common radeon fbcon tileblit ttm font bitblit softcursor ata_generic ahci libahci drm_kms_helper skge r8169 libata mii scsi_mod wmi acpi_cpufreq
[  568.938539] CPU: 1 PID: 3300 Comm: init Tainted: G        W     3.16.0-rc5upstream-01651-g03b9189 #1
[  568.947946] Hardware name: ECS A780GM-A Ultra/A780GM-A Ultra, BIOS 080015  04/01/2010
[  568.956008]  00000209 ed0f1cd0 c1617946 c175403c ed0f1d00 c1090c3f c1754084 ed0f1d2c
[  568.964068]  00000ce4 c175403c 00000209 c11f22a5 c11f22a5 f755e8c0 ed0f1d78 f755e90d
[  568.972128]  ed0f1d18 c1090cde 00000009 ed0f1d10 c1754084 ed0f1d2c ed0f1d60 c11f22a5
[  568.980194] Call Trace:
[  568.982715]  [<c1617946>] dump_stack+0x48/0x60
[  568.987294]  [<c1090c3f>] warn_slowpath_common+0x7f/0xa0
[  569.003887]  [<c1090cde>] warn_slowpath_fmt+0x2e/0x30
[  569.009092]  [<c11f22a5>] remove_proc_entry+0x165/0x170
[  569.014476]  [<c10da6ca>] unregister_irq_proc+0xaa/0xc0
[  569.019858]  [<c10d582f>] free_desc+0x1f/0x60
[  569.024346]  [<c10d58aa>] irq_free_descs+0x3a/0x80
[  569.029283]  [<c10d9e9d>] irq_dispose_mapping+0x2d/0x50
[  569.034666]  [<c1078fd3>] mp_unmap_irq+0x73/0xa0
[  569.039423]  [<c107196b>] acpi_unregister_gsi_ioapic+0x2b/0x40
[  569.045431]  [<c107180f>] acpi_unregister_gsi+0xf/0x20
[  569.050725]  [<c1339cad>] acpi_pci_irq_disable+0x4b/0x50
[  569.056196]  [<c14daa38>] pcibios_disable_device+0x18/0x20
[  569.061848]  [<c130123d>] do_pci_disable_device+0x4d/0x60
[  569.067410]  [<c13012b7>] pci_disable_device+0x47/0xb0
[  569.077814]  [<c14800b1>] usb_hcd_pci_shutdown+0x31/0x40
[  569.083285]  [<c1304b19>] pci_device_shutdown+0x19/0x50
[  569.088667]  [<c13fda64>] device_shutdown+0x14/0x120
[  569.093777]  [<c10ac29d>] kernel_restart_prepare+0x2d/0x30
[  569.099429]  [<c10ac41e>] kernel_restart+0xe/0x60
[  569.109028]  [<c10ac611>] SYSC_reboot+0x191/0x220
[  569.159269]  [<c10ac6ba>] SyS_reboot+0x1a/0x20
[  569.163843]  [<c161c718>] sysenter_do_call+0x12/0x16
[  569.168951] ---[ end trace ccc1ec4471c289c9 ]---

Tested-by: Aaron Lu <aaron.lu@intel.com>
Signed-off-by: Jiang Liu <jiang.liu@linux.intel.com>
Reviewed-by: Huang Rui <ray.huang@amd.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/usb/core/hcd-pci.c

@@ -380,6 +380,8 @@ void usb_hcd_pci_shutdown(struct pci_dev *dev)
 	if (test_bit(HCD_FLAG_HW_ACCESSIBLE, &hcd->flags) &&
 			hcd->driver->shutdown) {
 		hcd->driver->shutdown(hcd);
+		if (usb_hcd_is_primary_hcd(hcd) && hcd->irq > 0)
+			free_irq(hcd->irq, hcd);
 		pci_disable_device(dev);
 	}
 }