net/{packet,tstun}: fix typo in test helper docs

Change-Id: Ifc1684fe77c7d2585e049e0dfd7340910c47a67a
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>

net/packet/packet_test.go

@@ -445,7 +445,7 @@ func TestParsedString(t *testing.T) {
 }
 
 // mustHexDecode is like hex.DecodeString, but panics on error
-// and ignores whitespcae in s.
+// and ignores whitespace in s.
 func mustHexDecode(s string) []byte {
 	return must.Get(hex.DecodeString(strings.Map(func(r rune) rune {
 		if unicode.IsSpace(r) {

net/tstun/wrap_test.go

@@ -297,7 +297,7 @@ func TestWriteAndInject(t *testing.T) {
 }
 
 // mustHexDecode is like hex.DecodeString, but panics on error
-// and ignores whitespcae in s.
+// and ignores whitespace in s.
 func mustHexDecode(s string) []byte {
 	return must.Get(hex.DecodeString(strings.Map(func(r rune) rune {
 		if unicode.IsSpace(r) {