cw1200: handle allocation failure in wsm_event_indication()

Check for allocation failures and return -ENOMEM.  The caller
already expects it.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/drivers/net/wireless/cw1200/wsm.c b/drivers/net/wireless/cw1200/wsm.c
index f3fd9b2..3ab25f6 100644
--- a/drivers/net/wireless/cw1200/wsm.c
+++ b/drivers/net/wireless/cw1200/wsm.c
@@ -929,6 +929,8 @@
 	}
 
 	event = kzalloc(sizeof(struct cw1200_wsm_event), GFP_KERNEL);
+	if (!event)
+		return -ENOMEM;
 
 	event->evt.id = __le32_to_cpu(WSM_GET32(buf));
 	event->evt.data = __le32_to_cpu(WSM_GET32(buf));