fixed 9a4e9677 from https://gitee.com/hgbveiu743/kernel_liteos_m/pulls/1009

fix:修复OsLs函数内存泄漏问题
当d = NULL时，path没有释放，现释放path所指向的内存

close #I6A07U
Signed-off-by: Nyinjiaming <yinjiaming@huawei.com>
Change-Id: Iee9fd8d2171c6fdcf353a48e7af385bbd1660520

components/shell/src/cmds/vfs_shellcmd.c

@@ -181,6 +181,7 @@ VOID OsLs(const CHAR *pathname)
     d = opendir(path);
     if (d == NULL) {
         PRINT_ERR("No such directory = %s\n", path);
+        free(path);
     } else {
         PRINTK("Directory %s:\n", path);
         do {