net: misc: Remove extern from function prototypes

There are a mix of function prototypes with and without extern
in the kernel sources.  Standardize on not using extern for
function prototypes.

Function prototypes don't need to be written with extern.
extern is assumed by the compiler.  Its use is as unnecessary as
using auto to declare automatic/local variables in a block.

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/mac80211/rate.h

@@ -144,8 +144,8 @@ void rate_control_deinitialize(struct ieee80211_local *local);
 
 /* Rate control algorithms */
 #ifdef CONFIG_MAC80211_RC_PID
-extern int rc80211_pid_init(void);
-extern void rc80211_pid_exit(void);
+int rc80211_pid_init(void);
+void rc80211_pid_exit(void);
 #else
 static inline int rc80211_pid_init(void)
 {
@@ -157,8 +157,8 @@ static inline void rc80211_pid_exit(void)
 #endif
 
 #ifdef CONFIG_MAC80211_RC_MINSTREL
-extern int rc80211_minstrel_init(void);
-extern void rc80211_minstrel_exit(void);
+int rc80211_minstrel_init(void);
+void rc80211_minstrel_exit(void);
 #else
 static inline int rc80211_minstrel_init(void)
 {
@@ -170,8 +170,8 @@ static inline void rc80211_minstrel_exit(void)
 #endif
 
 #ifdef CONFIG_MAC80211_RC_MINSTREL_HT
-extern int rc80211_minstrel_ht_init(void);
-extern void rc80211_minstrel_ht_exit(void);
+int rc80211_minstrel_ht_init(void);
+void rc80211_minstrel_ht_exit(void);
 #else
 static inline int rc80211_minstrel_ht_init(void)
 {