chore: fix lint errors (#8288)

Author: crisbeto

src/lib/select/select.spec.ts

@@ -1870,7 +1870,6 @@ describe('MatSelect', () => {
 
         // There appears to be a small rounding error on IE, so we verify that the value is close,
         // not exact.
-        let platform = new Platform();
         if (platform.TRIDENT) {
           let difference =
               Math.abs(optionTop + (menuItemHeight - triggerHeight) / 2 - triggerTop);

src/material-examples/table-selection/table-selection-example.css

@@ -11,5 +11,5 @@
 }
 
 .mat-column-select {
-  overflow: initial;
+  overflow: visible;
 }