[bugfix] Sku: incorrect button border radius (#3966)

src/sku/components/SkuActions.tsx

@@ -29,7 +29,6 @@ function SkuActions(
     <div class={bem()} {...inherit(ctx)}>
       {props.showAddCartBtn && (
         <Button
-          square
           size="large"
           type="warning"
           text={props.addCartText || '加入购物车'}
@@ -37,7 +36,6 @@ function SkuActions(
         />
       )}
       <Button
-        square
         size="large"
         type="danger"
         text={props.buyText || '立即购买'}

src/sku/index.less

@@ -322,13 +322,16 @@
       font-size: @font-size-md;
       line-height: 34px;
       border: none;
+      border-radius: 0;
 
       &:first-of-type {
-        border-radius: 18px 0 0 18px;
+        border-top-left-radius: 18px;
+        border-bottom-left-radius: 18px;
       }
 
       &:last-of-type {
-        border-radius: 0 18px 18px 0;
+        border-top-right-radius: 18px;
+        border-bottom-right-radius: 18px;
       }
 
       &--warning {