Move erase to immediately before the paint call

Because we're doing a few operations, with type assertions, let's not have them
in between the erase and the paint.

spinner.go

@@ -373,11 +373,11 @@ func (s *Spinner) painter(cancel, sig chan struct{}) {
 
 			s.mu.Unlock()
 
-			_ = s.erase()
-
 			m, d := atomicString(s.message), atomicDuration(s.delayDuration)
 			cFn := atomicColorFn(s.colorFn)
 
+			_ = s.erase()
+
 			if err := s.paint(c, m, cFn); err != nil {
 				panic(fmt.Sprintf("failed to paint line: %v", err))
 			}