net: Remove unnecessary semicolons after switch statements

Also added an explicit break; to avoid
a fallthrough in net/ipv4/tcp_input.c

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
index 3284393..6596b4f 100644
--- a/net/ipv4/tcp.c
+++ b/net/ipv4/tcp.c
@@ -2215,7 +2215,7 @@
 	default:
 		/* fallthru */
 		break;
-	};
+	}
 
 	if (optlen < sizeof(int))
 		return -EINVAL;