um: irq: Remove IRQF_DISABLED

Since commit [e58aa3d2: genirq: Run irq handlers with interrupts disabled],
We run all interrupt handlers with interrupts disabled
and we even check and yell when an interrupt handler
returns with interrupts enabled (see commit [b738a50a:
genirq: Warn when handler enables interrupts]).

So now this flag is a NOOP and can be removed.

Signed-off-by: Yong Zhang <yong.zhang0@gmail.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
diff --git a/arch/um/drivers/xterm_kern.c b/arch/um/drivers/xterm_kern.c
index b646bcc..8bd130f 100644
--- a/arch/um/drivers/xterm_kern.c
+++ b/arch/um/drivers/xterm_kern.c
@@ -50,7 +50,7 @@
 	init_completion(&data->ready);
 
 	err = um_request_irq(XTERM_IRQ, socket, IRQ_READ, xterm_interrupt,
-			     IRQF_DISABLED | IRQF_SHARED | IRQF_SAMPLE_RANDOM,
+			     IRQF_SHARED | IRQF_SAMPLE_RANDOM,
 			     "xterm", data);
 	if (err) {
 		printk(KERN_ERR "xterm_fd : failed to get IRQ for xterm, "