make govet linter pass (#3292)

* make govet linter pass

Refs #3262

* close PipeReader and check for err

crypto/encoding/amino/encode_test.go

@@ -47,6 +47,8 @@ func checkAminoJSON(t *testing.T, src interface{}, dst interface{}, isNil bool)
 	require.Nil(t, err, "%+v", err)
 }
 
+// ExamplePrintRegisteredTypes refers to unknown identifier: PrintRegisteredTypes
+//nolint:govet
 func ExamplePrintRegisteredTypes() {
 	cdc.PrintTypes(os.Stdout)
 	// Output: | Type | Name | Prefix | Length | Notes |