Bluetooth: bnep: fix wild-memory-access in proto_unregister

There's issue as follows:
KASAN: maybe wild-memory-access in range [0xdead...108-0xdead...10f]
CPU: 3 UID: 0 PID: 2805 Comm: rmmod Tainted: G W
RIP: 0010:proto_unregister+0xee/0x400
Call Trace:
<TASK>
__do_sys_delete_module+0x318/0x580
do_syscall_64+0xc1/0x1d0
entry_SYSCALL_64_after_hwframe+0x77/0x7f

As bnep_init() ignore bnep_sock_init()'s return value, and bnep_sock_init()
will cleanup all resource. Then when remove bnep module will call
bnep_sock_cleanup() to cleanup sock's resource.
To solve above issue just return bnep_sock_init()'s return value in
bnep_exit().

Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Ye Bin <[e-mail]>
Signed-off-by: Luiz Augusto von Dentz <[e-mail]>

net/bluetooth/bnep/core.c

···
 	if (flt[0])
 		BT_INFO("BNEP filters: %s", flt);
 
-	bnep_sock_init();
-	return 0;
+	return bnep_sock_init();
 }
 
 static void __exit bnep_exit(void)