intel_th: Fix freeing IRQs

intel_th: Fix freeing IRQs

Commit aac8da65174a ("intel_th: msu: Start handling IRQs") implicitly
relies on the use of devm_request_irq() to subsequently free the irqs on
device removal, but in case of the pci_free_irq_vectors() API, the
handlers need to be freed before it is called. Therefore, at the moment
the driver's remove path trips a BUG_ON(irq_has_action()):

> kernel BUG at drivers/pci/msi.c:375!
> invalid opcode: 0000 1 SMP
> CPU: 2 PID: 818 Comm: rmmod Not tainted 5.5.0-rc1+ #1
> RIP: 0010:free_msi_irqs+0x67/0x1c0
> pci_disable_msi+0x116/0x150
> pci_free_irq_vectors+0x1b/0x20
> intel_th_pci_remove+0x22/0x30 [intel_th_pci]
> pci_device_remove+0x3e/0xb0
> device_release_driver_internal+0xf0/0x1c0
> driver_detach+0x4c/0x8f
> bus_remove_driver+0x5c/0xd0
> driver_unregister+0x31/0x50
> pci_unregister_driver+0x40/0x90
> intel_th_pci_driver_exit+0x10/0xad6 [intel_th_pci]
> __x64_sys_delete_module+0x147/0x290
> ? exit_to_usermode_loop+0xd7/0x120
> do_syscall_64+0x57/0x1b0
> entry_SYSCALL_64_after_hwframe+0x44/0xa9

Fix this by explicitly freeing irqs before freeing the vectors. We keep
using the devm_* variants because they are still useful in early error
paths.

Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Fixes: aac8da65174a ("intel_th: msu: Start handling IRQs")
Reported-by: Ammy Yi <ammy.yi@intel.com>
Tested-by: Ammy Yi <ammy.yi@intel.com>
Cc: stable@vger.kernel.org # v5.2+
Link: https://lore.kernel.org/r/20191217115527.74383-4-alexander.shishkin@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>