fixes #9392: no need for width auto on inline/navbar form controls given inline-block on parent form group

less/forms.less

@@ -311,11 +311,6 @@ textarea {
       vertical-align: middle;
     }
 
-    // Reset form control's default 100% width
-    .form-control {
-      width: auto;
-    }
-
     // Remove default margin on radios/checkboxes that were used for stacking, and
     // then undo the floating of radios and checkboxes to match (which also avoids
     // a bug in WebKit: https://github.com/twbs/bootstrap/issues/1969).