usb: xhci: print xhci->xhc_state when queue_command failed

When encounters some errors like these:
xhci_hcd 0000:4a:00.2: xHCI dying or halted, can't queue_command
xhci_hcd 0000:4a:00.2: FIXME: allocate a command ring segment
usb usb5-port6: couldn't allocate usb_device

It's hard to know whether xhc_state is dying or halted. So it's better
to print xhc_state's value which can help locate the resaon of the bug.

Signed-off-by: Su Hui <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Greg Kroah-Hartman <[e-mail]>

drivers/usb/host/xhci-ring.c

···
 
 	if ((xhci->xhc_state & XHCI_STATE_DYING) ||
 		(xhci->xhc_state & XHCI_STATE_HALTED)) {
-		xhci_dbg(xhci, "xHCI dying or halted, can't queue_command\n");
+		xhci_dbg(xhci, "xHCI dying or halted, can't queue_command. state: 0x%x\n",
+			 xhci->xhc_state);
 		return -ESHUTDOWN;
 	}