lguest: tidy up documentation

After Adrian Bunk's "make async_hcall static" moved things around, update
comments to match (aka "make Guest").

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

arch/x86/lguest/boot.c

@@ -93,27 +93,7 @@ struct lguest_data lguest_data = {
 };
 static cycle_t clock_base;
 
-/*G:035 Notice the lazy_hcall() above, rather than hcall().  This is our first
+/*G:037 async_hcall() is pretty simple: I'm quite proud of it really.  We have a
- * real optimization trick!
- *
- * When lazy_mode is set, it means we're allowed to defer all hypercalls and do
- * them as a batch when lazy_mode is eventually turned off.  Because hypercalls
- * are reasonably expensive, batching them up makes sense.  For example, a
- * large munmap might update dozens of page table entries: that code calls
- * paravirt_enter_lazy_mmu(), does the dozen updates, then calls
- * lguest_leave_lazy_mode().
- *
- * So, when we're in lazy mode, we call async_hypercall() to store the call for
- * future processing.  When lazy mode is turned off we issue a hypercall to
- * flush the stored calls.
- */
-static void lguest_leave_lazy_mode(void)
-{
-	paravirt_leave_lazy(paravirt_get_lazy_mode());
-	hcall(LHCALL_FLUSH_ASYNC, 0, 0, 0);
-}
-
-/* async_hcall() is pretty simple: I'm quite proud of it really.  We have a
  * ring buffer of stored hypercalls which the Host will run though next time we
  * do a normal hypercall.  Each entry in the ring has 4 slots for the hypercall
  * arguments, and a "hcall_status" word which is 0 if the call is ready to go,
@@ -151,6 +131,18 @@ static void async_hcall(unsigned long call, unsigned long arg1,
 	local_irq_restore(flags);
 }
 
+/*G:035 Notice the lazy_hcall() above, rather than hcall().  This is our first
+ * real optimization trick!
+ *
+ * When lazy_mode is set, it means we're allowed to defer all hypercalls and do
+ * them as a batch when lazy_mode is eventually turned off.  Because hypercalls
+ * are reasonably expensive, batching them up makes sense.  For example, a
+ * large munmap might update dozens of page table entries: that code calls
+ * paravirt_enter_lazy_mmu(), does the dozen updates, then calls
+ * lguest_leave_lazy_mode().
+ *
+ * So, when we're in lazy mode, we call async_hcall() to store the call for
+ * future processing. */
 static void lazy_hcall(unsigned long call,
 		       unsigned long arg1,
 		       unsigned long arg2,
@@ -161,7 +153,14 @@ static void lazy_hcall(unsigned long call,
 	else
 		async_hcall(call, arg1, arg2, arg3);
 }
-/*:*/
+
+/* When lazy mode is turned off reset the per-cpu lazy mode variable and then
+ * issue a hypercall to flush any stored calls. */
+static void lguest_leave_lazy_mode(void)
+{
+	paravirt_leave_lazy(paravirt_get_lazy_mode());
+	hcall(LHCALL_FLUSH_ASYNC, 0, 0, 0);
+}
 
 /*G:033
  * After that diversion we return to our first native-instruction