Revert "USB: pxa2xx_udc: fix hardcoded irq number"

This reverts commit d2487cb4257dafb686f682285854fe7f02ca29d8.

Russell King points out that it's obviously bogus, and I have to agree.
Not only does "irq" not even exist in that scope, but we obviously need
to free the irq that we actually requested, and that's IRQ_USB.

Reported-by: Russell King <[e-mail]>
Cc: Andrew Morton <[e-mail]>
Cc: Greg KH <[e-mail]>
Cc: David Brownell <[e-mail]>,
Cc: Milan Svoboda <[e-mail]>
Signed-off-by: Linus Torvalds <[e-mail]>

drivers/usb/gadget/pxa2xx_udc.c

···
 		if (retval != 0) {
 			printk(KERN_ERR "%s: can't get irq %i, err %d\n",
 				driver_name, vbus_irq, retval);
-			free_irq(irq, dev);
+			free_irq(IRQ_USB, dev);
 			return -EBUSY;
 		}
 	}