exec: fix ram_list dirty map optimization

The ae2810c4 patch introduced
optimization for ram_list.dirty_memory update. However it can only
work correctly if hpratio is 1 as the @bitmap parameter stores 1 bits
per system page size (may vary, 4K or 64K on PPC64) and
ram_list.dirty_memory stores 1 bit per TARGET_PAGE_SIZE
(which is hardcoded to 4K).

This fixes hpratio!=1 case to fall back to the slow path.
Signed-off-by: NAlexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: NJuan Quintela <quintela@redhat.com>

include/exec/ram_addr.h

@@ -93,7 +93,8 @@ static inline void cpu_physical_memory_set_dirty_lebitmap(unsigned long *bitmap,
     unsigned long page = BIT_WORD(start >> TARGET_PAGE_BITS);
 
     /* start address is aligned at the start of a word? */
-    if (((page * BITS_PER_LONG) << TARGET_PAGE_BITS) == start) {
+    if ((((page * BITS_PER_LONG) << TARGET_PAGE_BITS) == start) &&
+        (hpratio == 1)) {
         long k;
         long nr = BITS_TO_LONGS(pages);