fix typo

Signed-off-by: cuishuang <imcusg@gmail.com>

spew/internalunsafe_test.go

@@ -46,7 +46,7 @@ func changeKind(v *reflect.Value, readOnly bool) {
 	*flags |= flagKindMask
 }
 
-// TestAddedReflectValue tests functionaly of the dump and formatter code which
+// TestAddedReflectValue tests functional of the dump and formatter code which
 // falls back to the standard fmt library for new types that might get added to
 // the language.
 func TestAddedReflectValue(t *testing.T) {