Update hello.scratch to use namespacing struct

src/hello/hello.d

@@ -5,7 +5,7 @@ module hello.hello;
 
 import uefi;
 import console = hello.console;
-import scratch = hello.scratch;
+import hello.scratch;
 import hulk.bootinfo;
 import hulk.header;
 import hos.page_table;

src/hello/scratch.d

@@ -3,16 +3,18 @@
  */
 module hello.scratch;
 
+struct scratch
+{
     /* Scratch buffer. */
-private align(4096) __gshared ubyte[1024 * 1024] scratch;
+    private static align(4096) __gshared ubyte[1024 * 1024] scratch;
 
     /* Number of scratch buffer bytes used. */
-private __gshared size_t scratch_used;
+    private static __gshared size_t scratch_used;
 
     /**
      * Get the number of free bytes in the scratch buffer.
      */
-size_t free()
+    public static size_t free()
     {
         return scratch.sizeof - scratch_used;
     }
@@ -20,7 +22,7 @@ size_t free()
     /**
      * Get the current free scratch buffer address.
      */
-ubyte * current()
+    public static ubyte * current()
     {
         return &scratch[scratch_used];
     }
@@ -28,9 +30,10 @@ ubyte * current()
     /**
      * Allocate pages from the scratch buffer.
      */
-ubyte * alloc(size_t n = 1)
+    public static ubyte * alloc(size_t n = 1)
     {
         ubyte * address = &scratch[scratch_used];
         scratch_used += 4096u * n;
         return address;
     }
+}