rm unused $state param from form-control-validation mixin

Created by: cvrebert

Fixes #17323 (closed).

scss/mixins/_forms.scss

@@ -3,7 +3,7 @@
 // Used in _forms.scss to generate the form validation CSS for warnings, errors,
 // and successes.
 
-@mixin form-control-validation($state, $color) {
+@mixin form-control-validation($color) {
   // Color the label and help text
   .help-block,
   .control-label,

scss/_forms.scss

@@ -273,7 +273,7 @@ input[type="checkbox"] {
 
 // Form validation states
 .has-success {
-  @include form-control-validation(success, $brand-success);
+  @include form-control-validation($brand-success);
 
   .form-control-success {
     background-image: url($form-icon-success);
@@ -281,7 +281,7 @@ input[type="checkbox"] {
 }
 
 .has-warning {
-  @include form-control-validation(warning, $brand-warning);
+  @include form-control-validation($brand-warning);
 
   .form-control-warning {
     background-image: url($form-icon-warning);
@@ -289,7 +289,7 @@ input[type="checkbox"] {
 }
 
 .has-error {
-  @include form-control-validation(error, $brand-danger);
+  @include form-control-validation($brand-danger);
 
   .form-control-error {
     background-image: url($form-icon-error);