xhci: Free the command allocated for setting LPM if we return early

The command allocated to set exit latency LPM values need to be freed in
case the command is never queued. This would be the case if there is no
change in exit latency values, or device is missing.

Reported-by: Mirsad Goran Todorovac <mirsad.todorovac@alu.unizg.hr>
Link: https://lore.kernel.org/linux-usb/24263902-c9b3-ce29-237b-1c3d6918f4fe@alu.unizg.hr
Tested-by: Mirsad Goran Todorovac <mirsad.todorovac@alu.unizg.hr>
Fixes: 5c2a380 ("xhci: Allocate separate command structures for each LPM command")
Cc: <Stable@vger.kernel.org>
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Link: https://lore.kernel.org/r/20230330143056.1390020-4-mathias.nyman@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Author: matnyman

drivers/usb/host/xhci.c

@@ -4442,6 +4442,7 @@ static int __maybe_unused xhci_change_max_exit_latency(struct xhci_hcd *xhci,
 
 	if (!virt_dev || max_exit_latency == virt_dev->current_mel) {
 		spin_unlock_irqrestore(&xhci->lock, flags);
+		xhci_free_command(xhci, command);
 		return 0;
 	}