util: trim trailing space for files src/util/**/*

Using the following bash script doing that
```
cd src/util
find . -type f -print0 | xargs -0 -n1 sed -i 's/[ \t]*$//'
```

Signed-off-by: Yonggang Luo <luoyonggang@gmail.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/15093>

src/util/u_debug_stack.c

@@ -1,5 +1,5 @@
 /**************************************************************************
- * 
+ *
  * Copyright 2009 VMware, Inc.
  * All Rights Reserved.
  *
@@ -75,7 +75,7 @@ symbol_name_cached(unw_cursor_t *cursor, unw_proc_info_t *pip)
          procname[1] = 0;
       }
 
-      if (asprintf(&name, "%s%s", procname, ret == -UNW_ENOMEM ? "..." : "") == -1) 
+      if (asprintf(&name, "%s%s", procname, ret == -UNW_ENOMEM ? "..." : "") == -1)
          name = "??";
       entry = _mesa_hash_table_insert(symbols_hash, addr, (void*)name);
    }