fix style (#18422)

components/steps/style/small.less

@@ -1,4 +1,4 @@
-.@{steps-prefix-cls}-small .@{steps-prefix-cls}-item-container {
+.@{steps-prefix-cls}-small {
   &.@{steps-prefix-cls}-horizontal:not(.@{steps-prefix-cls}-label-vertical)
     .@{steps-prefix-cls}-item {
     margin-right: 12px;
@@ -28,7 +28,6 @@
   }
   .@{steps-prefix-cls}-item-tail {
     top: 8px;
-    padding: 0 8px;
   }
   .@{steps-prefix-cls}-item-custom .@{steps-prefix-cls}-item-icon {
     width: inherit;