Improve readability follows go-staticcheck

AUTHORS

@@ -101,6 +101,7 @@ Xiuming Chen <cc at cxm.cc>
 Xuehong Chan <chanxuehong at gmail.com>
 Zhenye Xie <xiezhenye at gmail.com>
 Zhixin Wen <john.wenzhixin at gmail.com>
+Ziheng Lyu <zihenglv at gmail.com>
 
 # Organizations
 

dsn.go

@@ -426,7 +426,6 @@ func parseDSNParams(cfg *Config, params string) (err error) {
 		// Collation
 		case "collation":
 			cfg.Collation = value
-			break
 
 		case "columnsWithAlias":
 			var isBool bool

statement_test.go

@@ -36,7 +36,7 @@ func TestConvertDerivedByteSlice(t *testing.T) {
 		t.Fatal("Byte slice not convertible", err)
 	}
 
-	if bytes.Compare(output.([]byte), []byte("value")) != 0 {
+	if !bytes.Equal(output.([]byte), []byte("value")) {
 		t.Fatalf("Byte slice not converted, got %#v %T", output, output)
 	}
 }

utils.go

@@ -199,7 +199,7 @@ func parseByteYear(b []byte) (int, error) {
 			return 0, err
 		}
 		year += v * n
-		n = n / 10
+		n /= 10
 	}
 	return year, nil
 }