[PATCH] HID read busywait fix

Make a read of a HID device block until data is available. Without it, the
read goes into a busy-wait loop until data is available.

Cc: Greg KH <[e-mail]>
Acked-by: Vojtech Pavlik <[e-mail]>
Cc: Dmitry Torokhov <[e-mail]>
Signed-off-by: Andrew Morton <[e-mail]>
Signed-off-by: Linus Torvalds <[e-mail]>

drivers/usb/input/hiddev.c

···
 				}
 
 				schedule();
+				set_current_state(TASK_INTERRUPTIBLE);
 			}
 
 			set_current_state(TASK_RUNNING);