tools/tcpsynbl.py: several small improvements of coding style (iovisor#4415)

* tools/tcpsynbl.py: remove trailing semicolon
* tools/tcpsynbl.py: remove whitespaces in blank line

Author: yangxingwu

tools/tcpsynbl.py

@@ -32,7 +32,7 @@
 
 int do_entry(struct pt_regs *ctx) {
     struct sock *sk = (struct sock *)PT_REGS_PARM1(ctx);
-    
+
     backlog_key_t key = {};
     key.backlog = sk->sk_max_ack_backlog;
     key.slot = bpf_log2l(sk->sk_ack_backlog);
@@ -67,7 +67,7 @@
     b.attach_kprobe(event="tcp_v4_syn_recv_sock", fn_name="do_entry")
     b.attach_kprobe(event="tcp_v6_syn_recv_sock", fn_name="do_entry")
 
-print("Tracing SYN backlog size. Ctrl-C to end.");
+print("Tracing SYN backlog size. Ctrl-C to end.")
 
 try:
     sleep(99999999)