staging: rtl8192u: ieee80211: ieee80211_softmac: mark symbols static where possible

We get 5 warnings when building kernel with W=1:
drivers/staging/rtl8192u/ieee80211/ieee80211_softmac.c:287:13: warning: no previous declaration for 'softmac_ps_mgmt_xmit' [-Wmissing-declarations]
drivers/staging/rtl8192u/ieee80211/ieee80211_softmac.c:323:24: warning: no previous declaration for 'ieee80211_probe_req' [-Wmissing-declarations]
drivers/staging/rtl8192u/ieee80211/ieee80211_softmac.c:643:24: warning: no previous declaration for 'ieee80211_authentication_req' [-Wmissing-declarations]
drivers/staging/rtl8192u/ieee80211/ieee80211_softmac.c:981:24: warning: no previous declaration for 'ieee80211_association_req' [-Wmissing-declarations]
drivers/staging/rtl8192u/ieee80211/ieee80211_softmac.c:3094:24: warning: no previous declaration for 'ieee80211_disassociate_skb' [-Wmissing-declarations]

In fact, these functions are only used in the file in which they are
declared and don't need a declaration, but can be made static.
so this patch marks these functions with 'static'.
Signed-off-by: Baoyou Xie <baoyou.xie@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/rtl8192u/ieee80211/ieee80211_softmac.c

@@ -284,7 +284,8 @@ inline void softmac_mgmt_xmit(struct sk_buff *skb, struct ieee80211_device *ieee
 	}
 }
 
-inline void softmac_ps_mgmt_xmit(struct sk_buff *skb, struct ieee80211_device *ieee)
+static inline void
+softmac_ps_mgmt_xmit(struct sk_buff *skb, struct ieee80211_device *ieee)
 {
 
 	short single = ieee->softmac_features & IEEE_SOFTMAC_SINGLE_QUEUE;
@@ -320,7 +321,7 @@ inline void softmac_ps_mgmt_xmit(struct sk_buff *skb, struct ieee80211_device *i
 	//dev_kfree_skb_any(skb);//edit by thomas
 }
 
-inline struct sk_buff *ieee80211_probe_req(struct ieee80211_device *ieee)
+static inline struct sk_buff *ieee80211_probe_req(struct ieee80211_device *ieee)
 {
 	unsigned int len, rate_len;
 	u8 *tag;
@@ -640,8 +641,9 @@ void ieee80211_start_scan_syncro(struct ieee80211_device *ieee)
 }
 EXPORT_SYMBOL(ieee80211_start_scan_syncro);
 
-inline struct sk_buff *ieee80211_authentication_req(struct ieee80211_network *beacon,
-	struct ieee80211_device *ieee, int challengelen)
+static inline struct sk_buff *
+ieee80211_authentication_req(struct ieee80211_network *beacon,
+			     struct ieee80211_device *ieee, int challengelen)
 {
 	struct sk_buff *skb;
 	struct ieee80211_authentication *auth;
@@ -978,7 +980,9 @@ static void ieee80211_resp_to_probe(struct ieee80211_device *ieee, u8 *dest)
 }
 
 
-inline struct sk_buff *ieee80211_association_req(struct ieee80211_network *beacon,struct ieee80211_device *ieee)
+static inline struct sk_buff *
+ieee80211_association_req(struct ieee80211_network *beacon,
+			  struct ieee80211_device *ieee)
 {
 	struct sk_buff *skb;
 	//unsigned long flags;
@@ -3091,7 +3095,7 @@ static int ieee80211_wpa_set_encryption(struct ieee80211_device *ieee,
 	return ret;
 }
 
-inline struct sk_buff *ieee80211_disassociate_skb(
+static inline struct sk_buff *ieee80211_disassociate_skb(
 							struct ieee80211_network *beacon,
 							struct ieee80211_device *ieee,
 							u8	asRsn)