cls_cgroup.h netprio_cgroup.h: 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: NJoe Perches <joe@perches.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

include/net/cls_cgroup.h

@@ -24,7 +24,7 @@ struct cgroup_cls_state
 	u32 classid;
 };
 
-extern void sock_update_classid(struct sock *sk);
+void sock_update_classid(struct sock *sk);
 
 #if IS_BUILTIN(CONFIG_NET_CLS_CGROUP)
 static inline u32 task_cls_classid(struct task_struct *p)

include/net/netprio_cgroup.h

@@ -29,7 +29,7 @@ struct cgroup_netprio_state {
 	struct cgroup_subsys_state css;
 };
 
-extern void sock_update_netprioidx(struct sock *sk);
+void sock_update_netprioidx(struct sock *sk);
 
 #if IS_BUILTIN(CONFIG_NETPRIO_CGROUP)