Tiny code cleanup in user.module.

modules/user.module

@@ -171,7 +171,7 @@ function user_validate_name($name) {
 
 function user_validate_mail($mail) {
   if (!$mail) return t('You must enter an e-mail address.');
-  if ($mail && !valid_email_address($mail)) {
+  if (!valid_email_address($mail)) {
     return t('The e-mail address "%mail" is not valid.', array('%mail' => $mail));
   }
 }

modules/user/user.module

@@ -171,7 +171,7 @@ function user_validate_name($name) {
 
 function user_validate_mail($mail) {
   if (!$mail) return t('You must enter an e-mail address.');
-  if ($mail && !valid_email_address($mail)) {
+  if (!valid_email_address($mail)) {
     return t('The e-mail address "%mail" is not valid.', array('%mail' => $mail));
   }
 }