Bluetooth: Make amp_mgr_list and amp_mgr_list_lock static

There is no reason to have amp_mgr_list and amp_mgr_list_lock exported
from a2mp.c and thus make both of them static.
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>

net/bluetooth/a2mp.c

@@ -22,8 +22,8 @@
 #define A2MP_FEAT_EXT	0x8000
 
 /* Global AMP Manager list */
-LIST_HEAD(amp_mgr_list);
-DEFINE_MUTEX(amp_mgr_list_lock);
+static LIST_HEAD(amp_mgr_list);
+static DEFINE_MUTEX(amp_mgr_list_lock);
 
 /* A2MP build & send command helper functions */
 static struct a2mp_cmd *__a2mp_build(u8 code, u8 ident, u16 len, void *data)

net/bluetooth/a2mp.h

@@ -129,9 +129,6 @@ struct a2mp_physlink_rsp {
 #define A2MP_STATUS_PHYS_LINK_EXISTS		0x05
 #define A2MP_STATUS_SECURITY_VIOLATION		0x06
 
-extern struct list_head amp_mgr_list;
-extern struct mutex amp_mgr_list_lock;
-
 struct amp_mgr *amp_mgr_get(struct amp_mgr *mgr);
 int amp_mgr_put(struct amp_mgr *mgr);
 u8 __next_ident(struct amp_mgr *mgr);