cgroup: net_cls: Fix local variable type decleration

The classid type used throughout the kernel is u32.
Signed-off-by: NDaniel Wagner <daniel.wagner@bmw-carit.de>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Li Zefan <lizefan@huawei.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: <netdev@vger.kernel.org>
Cc: <cgroups@vger.kernel.org>
Acked-by: NNeil Horman <nhorman@tuxdriver.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

include/net/cls_cgroup.h

@@ -29,7 +29,7 @@ extern void sock_update_classid(struct sock *sk);
 #if IS_BUILTIN(CONFIG_NET_CLS_CGROUP)
 static inline u32 task_cls_classid(struct task_struct *p)
 {
-	int classid;
+	u32 classid;
 
 	if (in_interrupt())
 		return 0;