rst-malloc: adjust free_bytes in rst_mem_align_cpos

We need to adjust free_bytes each time when we change free_bytes.

Fixes #140
Signed-off-by: Andrew Vagin <avagin@virtuozzo.com>
Acked-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@virtuozzo.com>

criu/rst-malloc.c

@@ -128,8 +128,11 @@ unsigned long rst_mem_align_cpos(int type)
 {
 	struct rst_mem_type_s *t = &rst_mems[type];
 	BUG_ON(!t->remapable || !t->enabled);
+	void *ptr;
 
-	t->free_mem = (void *) round_up((unsigned long)t->free_mem, sizeof(void *));
+	ptr = (void *) round_up((unsigned long)t->free_mem, sizeof(void *));
+	t->free_bytes -= (ptr - t->free_mem);
+	t->free_mem = ptr;
 
 	return t->free_mem - t->buf;
 }