mac80211: mesh: fix potentially unaligned access

The pointer here points directly into the frame, so the
access is potentially unaligned. Use get_unaligned_le16
to avoid that.

Fixes: 3f52b7e3 ("mac80211: mesh power save basics")
Link: https://lore.kernel.org/r/20210920154009.3110ff75be0c.Ib6a2ff9e9cc9bc6fca50fce631ec1ce725cc926b@changeid

Signed-off-by: Johannes Berg <johannes.berg@intel.com>

net/mac80211/mesh_ps.c

@@ -2,6 +2,7 @@
 /*
  * Copyright 2012-2013, Marco Porsch <marco.porsch@s2005.tu-chemnitz.de>
  * Copyright 2012-2013, cozybit Inc.
+ * Copyright (C) 2021 Intel Corporation
  */
 
 #include "mesh.h"
@@ -588,7 +589,7 @@ void ieee80211_mps_frame_release(struct sta_info *sta,
 
 	/* only transmit to PS STA with announced, non-zero awake window */
 	if (test_sta_flag(sta, WLAN_STA_PS_STA) &&
-	    (!elems->awake_window || !le16_to_cpu(*elems->awake_window)))
+	    (!elems->awake_window || !get_unaligned_le16(elems->awake_window)))
 		return;
 
 	if (!test_sta_flag(sta, WLAN_STA_MPSP_OWNER))