go: Fix things staticcheck complains about

Client: go

Staticcheck is the recommended replacement of the frozen and deprecated
official golint linter [1].

Fix the things it complained about (or add lint:ignore directive) in:

- lib/go/thrift
- lib/go/test/tests
- tutorial/go/src
- test/go/src
- compiler generated code

The majority of the fixes are in the following categories:

- Use of deprecated function (mainly the TConfiguration related ones)
- Redundant break in switch cases
- Unused and unexported variables/fields/functions

Also in the same spirit as fb539ae, remove the error return from
NewTSSLSocket as it can never be non-nil.

This change will be cherry-picked into 0.15.0 branch after merged.

[1]: https://groups.google.com/g/golang-nuts/c/rCP70Aq_tBc
diff --git a/test/go/src/bin/testclient/main.go b/test/go/src/bin/testclient/main.go
index 39ee95b..f0ce052 100644
--- a/test/go/src/bin/testclient/main.go
+++ b/test/go/src/bin/testclient/main.go
@@ -36,7 +36,6 @@
 var transport = flag.String("transport", "buffered", "Transport: buffered, framed, http, zlib")
 var protocol = flag.String("protocol", "binary", "Protocol: binary, compact, json")
 var ssl = flag.Bool("ssl", false, "Encrypted Transport using SSL")
-var zlib = flag.Bool("zlib", false, "Wrapped Transport using Zlib")
 var testloops = flag.Int("testloops", 1, "Number of Tests")
 
 func main() {
@@ -131,6 +130,9 @@
 		binout[i] = byte(i)
 	}
 	bin, err := client.TestBinary(defaultCtx, binout)
+	if err != nil {
+		t.Fatalf("TestBinary failed with %v", err)
+	}
 	for i := 0; i < 256; i++ {
 		if binout[i] != bin[i] {
 			t.Fatalf("Unexpected TestBinary() result expected %d, got %d ", binout[i], bin[i])