[PATCH] net: mpls: Fix GCC 12 warning

[Victor Erminpour <victor.erminpour@oracle.com>]

When building with automatic stack variable initialization, GCC 12
complains about variables defined outside of switch case statements.
Move the variable outside the switch, which silences the warning:

./net/mpls/af_mpls.c:1624:21: error: statement will never be executed [-Werror=switch-unreachable]
  1624 |                 int err;
       |                     ^~~

Signed-off-by: Victor Erminpour <victor.erminpour@oracle.com>
---
 net/mpls/af_mpls.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/mpls/af_mpls.c b/net/mpls/af_mpls.c
index 48f75a56f4ae..d6fdc5782d33 100644
--- a/net/mpls/af_mpls.c
+++ b/net/mpls/af_mpls.c
@@ -1607,6 +1607,7 @@ static int mpls_dev_notify(struct notifier_block *this, unsigned long event,
 	struct net_device *dev = netdev_notifier_info_to_dev(ptr);
 	struct mpls_dev *mdev;
 	unsigned int flags;
+	int err;
 
 	if (event == NETDEV_REGISTER) {
 		mdev = mpls_add_dev(dev);
@@ -1621,7 +1622,6 @@ static int mpls_dev_notify(struct notifier_block *this, unsigned long event,
 		return NOTIFY_OK;
 
 	switch (event) {
-		int err;
 
 	case NETDEV_DOWN:
 		err = mpls_ifdown(dev, event);