typo fixes (#3169)

* spelling fixes

* its/it's

test/ds_file_test.go

@@ -8,7 +8,7 @@ import (
 	"github.com/miekg/dns"
 )
 
-// Using miek.nl here because this is the easiest zone to get access to and it's masters
+// Using miek.nl here because this is the easiest zone to get access to and its masters
 // run both NSD and BIND9, making checks like "what should we actually return" super easy.
 var dsTestCases = []mtest.Case{
 	{

test/secondary_test.go

@@ -71,7 +71,7 @@ func TestSecondaryZoneTransfer(t *testing.T) {
 	m.SetQuestion("example.org.", dns.TypeSOA)
 
 	var r *dns.Msg
-	// This is now async; we we need to wait for it to be transferred.
+	// This is now async; we need to wait for it to be transferred.
 	for i := 0; i < 10; i++ {
 		r, err = dns.Exchange(m, udp)
 		if len(r.Answer) != 0 {