kfifo: fix warn_unused_result

Fix the "ignoring return value of '...', declared with attribute
warn_unused_result" compiler warning in several users of the new kfifo
API.

It removes the __must_check attribute from kfifo_in() and
kfifo_in_locked() which must not necessary performed.

Fix the allocation bug in the nozomi driver file, by moving out the
kfifo_alloc from the interrupt handler into the probe function.

Fix the kfifo_out() and kfifo_out_locked() users to handle a unexpected
end of fifo.

Signed-off-by: Stefani Seibold <stefani@seibold.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/drivers/net/wireless/libertas/main.c b/drivers/net/wireless/libertas/main.c
index 2bcfa74..c2975c8 100644
--- a/drivers/net/wireless/libertas/main.c
+++ b/drivers/net/wireless/libertas/main.c
@@ -514,8 +514,10 @@
 		while (kfifo_len(&priv->event_fifo)) {
 			u32 event;
 
-			kfifo_out(&priv->event_fifo, (unsigned char *) &event,
-				sizeof(event));
+			if (kfifo_out(&priv->event_fifo,
+				(unsigned char *) &event, sizeof(event)) !=
+				sizeof(event))
+					break;
 			spin_unlock_irq(&priv->driver_lock);
 			lbs_process_event(priv, event);
 			spin_lock_irq(&priv->driver_lock);