Input: fix clear icon is not centered

Author: YiiGuxing

packages/theme-chalk/src/input.scss

@@ -80,7 +80,6 @@
   & .el-input__clear {
     color: $--input-icon-color;
     font-size: $--input-font-size;
-    line-height: 16px;
     cursor: pointer;
     transition: $--color-transition-base;