gtp: Fix inconsistent indenting

Fix the following warning as reported by smatch:

New smatch warnings:
drivers/net/gtp.c:1796 gtp_genl_send_echo_req() warn: inconsistent indenting

Fixes: d33bd75 ("gtp: Implement GTP echo request")
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Wojciech Drewek <wojciech.drewek@intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>

drivers/net/gtp.c

@@ -1793,7 +1793,7 @@ static int gtp_genl_send_echo_req(struct sk_buff *skb, struct genl_info *info)
 	if (IS_ERR(rt)) {
 		netdev_dbg(gtp->dev, "no route for echo request to %pI4\n",
 			   &dst_ip);
-			   kfree_skb(skb_to_send);
+		kfree_skb(skb_to_send);
 		return -ENODEV;
 	}