staging:rtl8187se:ieee80211: Fix sparse warning of cast to restricted __le16

This patch fixes the following sparse warnings:
drivers/staging/rtl8187se/ieee80211/ieee80211_crypt_tkip.c:496:17: warning: cast to restricted __le16
drivers/staging/rtl8187se/ieee80211/ieee80211_crypt_tkip.c:540:12: warning: cast to restricted __le16
drivers/staging/rtl8187se/ieee80211/ieee80211_crypt_tkip.c:586:12: warning: cast to restricted __le16

Signed-off-by: Himangi Saraogi <himangi774@gmail.com>
Reviewed-by: Bob Copeland <me@bobcopeland.com>
Signed-off-by: Peter P Waskiewicz Jr <peter.p.waskiewicz.jr@intel.com>
diff --git a/drivers/staging/rtl8187se/ieee80211/ieee80211.h b/drivers/staging/rtl8187se/ieee80211/ieee80211.h
index e4c1c37..d1763b7 100644
--- a/drivers/staging/rtl8187se/ieee80211/ieee80211.h
+++ b/drivers/staging/rtl8187se/ieee80211/ieee80211.h
@@ -482,7 +482,7 @@
 };
 
 struct ieee80211_hdr_4addr {
-	u16 frame_ctl;
+	__le16 frame_ctl;
 	u16 duration_id;
 	u8 addr1[ETH_ALEN];
 	u8 addr2[ETH_ALEN];