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/scsi/libsrp.c b/drivers/scsi/libsrp.c
index 8424b86..ab19b3b 100644
--- a/drivers/scsi/libsrp.c
+++ b/drivers/scsi/libsrp.c
@@ -163,8 +163,11 @@
 {
 	struct iu_entry *iue = NULL;
 
-	kfifo_out_locked(&target->iu_queue.queue, (void *) &iue,
-			sizeof(void *), &target->iu_queue.lock);
+	if (kfifo_out_locked(&target->iu_queue.queue, (void *) &iue,
+		sizeof(void *), &target->iu_queue.lock) != sizeof(void *)) {
+			WARN_ONCE(1, "unexpected fifo state");
+			return NULL;
+	}
 	if (!iue)
 		return iue;
 	iue->target = target;